Facit biologi kap 13 TESTA DIG SJÄLV 13.1 1 Kolhydrater, fett och
advertisement
ENGLISH
CELESTRON®
INSTRUCTION MANUAL
Ɣ NexStar 90 MAK
Ɣ NexStar 127 MAK
TABLE OF CONTENTS
INTRODUCTION ............................................................................................................................................................ 4
Warning .......................................................................................................................................................................... 4
ASSEMBLY ...................................................................................................................................................................... 6
Assembling the NexStar ................................................................................................................................................. 6
Attaching the Hand Control Holder ............................................................................................................................ 7
Attaching the Fork Arm to the Tripod......................................................................................................................... 7
Attaching the Telescope to the Fork Arm ................................................................................................................... 7
The Star Diagonal ....................................................................................................................................................... 7
The Eyepiece............................................................................................................................................................... 8
Focusing...................................................................................................................................................................... 8
The Star Pointer Finderscope ...................................................................................................................................... 8
Star Pointer Installation............................................................................................................................................... 9
Star Pointer Operation................................................................................................................................................. 9
Attaching the Hand Control ...................................................................................................................................... 10
Powering the NexStar ............................................................................................................................................... 10
HAND CONTROL ......................................................................................................................................................... 11
The Hand Control ..................................................................................................................................................... 11
Hand Control Operation................................................................................................................................................ 12
Alignment Procedure ................................................................................................................................................ 13
Sky Align .................................................................................................................................................................. 13
Auto Two-Star Align ................................................................................................................................................ 15
Two Star Alignment.................................................................................................................................................. 15
One-Star Align.......................................................................................................................................................... 16
Solar System Align ................................................................................................................................................... 16
NexStar Re-Alignment.............................................................................................................................................. 17
Object Catalog .............................................................................................................................................................. 17
Selecting an Object ................................................................................................................................................... 17
Slewing to an Object ................................................................................................................................................. 18
Finding Planets ......................................................................................................................................................... 18
Tour Mode ................................................................................................................................................................ 18
Constellation Tour .................................................................................................................................................... 18
Direction Buttons .......................................................................................................................................................... 19
Rate Button ............................................................................................................................................................... 19
Set Up Procedures......................................................................................................................................................... 19
Tracking Mode.......................................................................................................................................................... 19
Tracking Rate............................................................................................................................................................ 20
View Time-Site......................................................................................................................................................... 20
User Defined Objects ................................................................................................................................................ 20
Get R.A./DEC. .......................................................................................................................................................... 20
Goto R.A./DEC......................................................................................................................................................... 20
Identify...................................................................................................................................................................... 21
Scope Setup Features .................................................................................................................................................... 21
Anti-backlash ............................................................................................................................................................ 21
Slew Limits ............................................................................................................................................................... 21
Filter Limits .............................................................................................................................................................. 21
Direction Buttons ...................................................................................................................................................... 22
Goto Approach.......................................................................................................................................................... 22
Cordwrap .................................................................................................................................................................. 22
Utility Features ............................................................................................................................................................. 22
GPS On/Off............................................................................................................................................................... 22
Light Control............................................................................................................................................................. 22
Factory Setting.......................................................................................................................................................... 22
Version...................................................................................................................................................................... 22
Get Axis Position ...................................................................................................................................................... 22
Goto Axis Position.................................................................................................................................................... 22
Hibernate................................................................................................................................................................... 22
Sun Menu.................................................................................................................................................................. 23
2
Scrolling Menu ......................................................................................................................................................... 23
Calibrate Goto........................................................................................................................................................... 23
Set Mount Position.................................................................................................................................................... 23
TELESCOPE BASICS ................................................................................................................................................... 25
Focusing.................................................................................................................................................................... 25
Image Orientation ..................................................................................................................................................... 25
Calculating Magnification......................................................................................................................................... 26
Determining Field of View ....................................................................................................................................... 26
General Observing Hints........................................................................................................................................... 26
CELESTIAL OBSERVING........................................................................................................................................... 27
Observing the Moon ................................................................................................................................................. 27
Lunar Observing Hints.............................................................................................................................................. 27
Observing the Planets................................................................................................................................................ 27
Planetary Observing Hints ........................................................................................................................................ 27
Observing the Sun..................................................................................................................................................... 27
Solar Observing Hints............................................................................................................................................... 28
Observing Deep Sky Objects .................................................................................................................................... 28
Seeing Conditions ..................................................................................................................................................... 28
Transparency............................................................................................................................................................. 28
Sky Illumination........................................................................................................................................................ 28
Seeing ....................................................................................................................................................................... 29
TELESCOPE MAINTENANCE ................................................................................................................................... 30
Care and Cleaning of the Optics ................................................................................................................................... 30
Collimation ................................................................................................................................................................... 30
OPTIONAL ACCESSORIES....................................................................................................................................... 32
APPENDIX A - TECHNICAL SPECIFICATIONS.................................................................................................. 34
APPENDIX B – GLOSSARY OF TERMS................................................................................................................... 35
APPENDIX C – RS-232 CONNECTION ..................................................................................................................... 38
APPENDIX D – TIME ZONE MAPS ........................................................................................................................... 39
SKY MAPS...................................................................................................................................................................... 41
3
Congratulations on your purchase of the Celestron NexStar telescope! The NexStar ushers in a whole new
generation of computer automated technology. Simple and friendly to use, the NexStar is up and running after
locating just three bright celestial objects. It’s the perfect combination of power and portability. If you are new to
astronomy, you may wish to start off by using the NexStar's built-in Sky Tour feature, which commands the
NexStar to find the most interesting objects in the sky and automatically slews to each one. Or if you are more
experienced, you will appreciate the comprehensive database of over 4,000 objects, including customized lists of
all the best deep-sky objects, planets, bright double stars. No matter at what level you are starting out, the NexStar
will unfold for you and your friends all the wonders of the Universe.
Some of the many standard features of the NexStar include:
y
Incredible 3°/second slew speed.
y
Fully enclosed motors and optical encoders for position location.
y
Computerized hand controller with 4,000 object database.
y
Storage for programmable user defined objects; and
y
Many other high performance features!
The NexStar’s deluxe features combined with Celestron’s legendary optical standards give amateur astronomers
one of the most sophisticated and easy to use telescopes available on the market today.
Take time to read through this manual before embarking on your journey through the Universe. It may take a few
observing sessions to become familiar with your NexStar, so you should keep this manual handy until you have
fully mastered your telescope’s operation. The NexStar hand control has built-in instructions to guide you
through all the alignment procedures needed to have the telescope up and running in minutes. Use this manual in
conjunction with the on-screen instructions provided by the hand control. The manual gives detailed information
regarding each step as well as needed reference material and helpful hints guaranteed to make your observing
experience as simple and pleasurable as possible.
Your NexStar telescope is designed to give you years of fun and rewarding observations. However, there are a few
things to consider before using your telescope that will ensure your safety and protect your equipment.
Warning
Never look directly at the sun with the naked eye or with a telescope (unless you have the
proper solar filter). Permanent and irreversible eye damage may result.
Never use your telescope to project an image of the sun onto any surface. Internal heat build-up can
damage the telescope and any accessories attached to it.
Never use an eyepiece solar filter or a Herschel wedge. Internal heat build-up inside the telescope
can cause these devices to crack or break, allowing unfiltered sunlight to pass through to the eye.
Never leave the telescope unsupervised, either when children are present or adults who may not be
familiar with the correct operating procedures of your telescope.
4
11
12
1
10
2
9
3
4
5
6
8
7
=
The NexStar SLT Telescope
(NexStar 127MAK Shown)
1
2
3
4
5
6
Corrector Lens
Fork Arm
Battery Compartment
Tripod Coupling Screw
Tripod
Accessory Tray
7
8
9
10
11
12
5
Tripod Leg Extension Clamp
Hand Control
Star Diagonal
Eyepiece
Star Pointer Finderscope
Telescope Tube
The NexStar comes partially assembled and can be operational in a matter of minutes. The NexStar is conveniently
packaged in one reusable shipping carton that contains the following accessories:
y
y
y
y
y
y
y
25mm and 9mm Eyepieces – 1¼"
1¼" Star Diagonal
Star Pointer Finderscope and Mounting Bracket
Deluxe Accessory Tray
The Sky™ X Astronomy Software
NSOL Telescope Control Software
NexStar Hand Control w/ Object Database
Assembling the NexStar
Your NexStar comes in three major sections: the optical tube, the fork arm and the tripod. These sections can be
attached in seconds using the quick release coupling screw located under the tripod mounting platform and the dovetail
mounting clamp located on the inside of the fork arm. To begin, remove all of the accessories from their individual
boxes. Remember to save all of the containers so that they can be used to transport the telescope. Before attaching the
visual accessories, the telescope tube should be mounted to its tripod. First, install the accessory tray onto the tripod
legs:
1.
Remove the tripod from the box and spread the legs apart
until the center leg brace is fully extended.
2.
Locate the accessory tray, and place it on top of the tripod
center support brace in between the tripod legs (see figure 2-1).
3.
Rotate the accessory tray so that the central hole in the tray
slides over the flange post in the center of the support
bracket.
4.
Finally, rotate the tray so that the locking tabs slide under
the locking clips on support bracket. You will here the tray
snap into place.
Flange Post
Locking
Clips
Locking Tabs
Figure 2-1
It is a good idea to level the tripod and adjust the height of the tripod legs before attaching the fork arm and tube. Minor
adjustments can be made later. To adjust the height of the tripod legs:
1.
Loosen the tripod leg locking bolt located on the side of each leg.
2.
Slide the inner portion of each leg down 6" to 8" inches.
3.
Adjust the tripod height until the bubble level on the tripod leg is centered.
4.
Tighten the tripod locking bolts to hold each leg in place.
Bubble
Level
Figure 2-2
6
Attaching the Hand Control Holder
The NexStar comes with a snap-on hand control holder that conveniently attaches to any of
the tripod legs. To attach the hand control holder simply position the holder with the square
plastic tab facing up and push against the tripod leg until it snaps in to place.
Attaching the Fork Arm to the Tripod
With the tripod properly assembled, the telescope tube and fork arm can easily be attached
using the quick release coupling screw located underneath the tripod mounting platform:
1.
Place the fork arm base inside the tripod mounting platform.
2.
Thread the coupling screw into the hole at the bottom of the fork arm base and hand
tighten.
Figure 2-3
Fork Arm
Base
Coupling
Screw
Tripod Mounting
Platform
Figure 2-4
Attaching the Telescope to the Fork Arm
Your telescope optical tube has a built on dovetail mounting bar used to attach the tube to the fork arm. To attach the telescope
tube:
1.
2.
3.
Loosen the tube clamp tightening knob.
Slide the dovetail mounting bar of the telescope tube into the fork arm clamp.
Make sure that the logo on the side of the tube is right side up when the tube is
aligned with the fork arm.
Tighten the tube clamp knob by hand to secure the tube to the fork arm.
Dovetail
Mounting Bar
Your NexStar is fully assembled and is ready to attach the accessories.
The Star Diagonal
The star diagonal diverts the light at a right angle from the light path of the telescope.
For astronomical observing, this allows you to observe in positions that are more
comfortable than if you were to look straight through. To attach the star diagonal:
Tube Clamp
Tightening Knob
Figure 2-5
1.
2.
3.
Turn the thumbscrew on the eyepiece adapter at the end of the focuser barrel until it no
longer extends into (i.e., obstructs) the inner diameter of the focus barrel. Remove the protective dust cap from the focuser
barrel.
Slide the chrome portion of the star diagonal into the eyepiece adapter.
Tighten the thumbscrew on the eyepiece adapter to hold the star diagonal in place.
If you wish to change the orientation of the star diagonal, loosen the thumbscrew on the eyepiece adapter until the star diagonal
rotates freely. Rotate the diagonal to the desired position and tighten the thumbscrew.
7
The Eyepiece
The eyepiece, is the optical element that magnifies the image focused by the telescope. The eyepiece fits directly into the star
diagonal. To install the eyepiece:
1.
Loosen the thumbscrew on the star diagonal so it does not obstruct the inner
diameter of the eyepiece end of the diagonal. Remove the protective dust cap
from the star diagonal's barrel.
2.
Slide the chrome portion of the low power 25mm eyepiece into the star
diagonal.
3.
Tighten the thumbscrew to hold the eyepiece in place.
Star Pointer
Finderscope
Eyepiece
Star
Diagonal
To remove the eyepiece, loosen the thumbscrew on the star diagonal and slide the
eyepiece out.
Focuser Knob
Eyepieces are commonly referred to by focal length and barrel diameter.
Figure 2-6
The focal length of each eyepiece is printed on the eyepiece barrel. The longer
Visual accessories for the NexStar 90 & 127
the focal length (i.e., the larger the number) the lower the eyepiece power or
MAK models
magnification; and the shorter the focal length (i.e., the smaller the number) the
higher the magnification. Generally, you will use low-to-moderate power when viewing. For more information on how to
determine power, see the section on “Calculating Magnification.”
Barrel diameter is the diameter of the barrel that slides into the star diagonal or focuser. The NexStar uses eyepieces with a
standard 1-1/4" barrel diameter.
Focusing
The NexStar's focusing mechanism controls the primary mirror which is mounted on a ring that slides back and forth on the primary
baffle tube. The focusing knob, which moves the primary mirror, is on the rear cell of the telescope just below the star diagonal and
eyepiece. Turn the focusing knob until the image is sharp. If the knob will not turn, it has reached the end of its travel on the
focusing mechanism. Turn the knob in the opposite direction until the image is sharp. Once an image is in focus, turn the knob
clockwise to focus on a closer object and counterclockwise for a more distant object. A single turn of the focusing knob moves the
primary mirror only slightly. Therefore, it will take many turns (about 25) to go from close focus (approximately 20 feet) to
infinity.
For astronomical viewing, out of focus star images are very diffuse, making them difficult to see. If you turn the focus knob too
quickly, you can go right through focus without seeing the image. To avoid this problem, your first astronomical target should be a
bright object (like the Moon or a planet) so that the image is visible even when out of focus. Critical focusing is best accomplished
when the focusing knob is turned in such a manner that the mirror moves against the pull of gravity. In doing so, any mirror shift is
minimized. For astronomical observing, both visually and photographically, this is done by turning the focus knob
counterclockwise.
The Star Pointer Finderscope
The Star Pointer is the quickest and easiest way to point your telescope exactly at a desired object in the sky. It's like having a laser
pointer that you can shine directly onto the night sky. The Star Pointer is a zero magnification pointing tool that uses a coated glass
window to superimpose the image of a small red dot onto the night sky. While keeping both eyes open when looking through the
Star Pointer, simply move your telescope until the red dot, seen through the Star Pointer, merges with the object as seen with your
unaided eye. The red dot is produced by a light-emitting diode (LED); it is not a laser beam and will not damage the glass window
or your eye. The Star Pointer comes equipped with a variable brightness control, two axes alignment control and mounting brackets.
Before the Star Pointer is ready to be used, it must be attached to the telescope tube and properly aligned:
8
Sight Tube
ON/OFF
Brightness Control
Azimuth
Adjustment
Control
Battery
Compartment
(not shown)
Dovetail
Tightening
Screw
Altitude
Adjustment
Control
Dovetail Mount
Figure 2-8
The Star Pointer Finderscope with Bracket
Star Pointer Installation
1.
Slide the Star Pointer bracket into the dovetail mounting platform on top of the
focuser assembly (see figure 2-9).
2.
Orient the Star Pointer so that the sight tube is facing towards the front of the tube.
3.
Secure the Star Pointer bracket by tightening the thumb screw on the mounting
platform.
Thumb Screw
Star Pointer Operation
The star pointer is powered by a long life 3-volt lithium battery (#CR2032) located
underneath the front portion of the Star Pointer. Like all finderscopes, the Star Pointer
must be properly aligned with the main telescope before it can be used. This is a simple
process using the azimuth and altitude control knobs located on the side and bottom of
the Star Pointer. The alignment procedure is best done at night since the LED dot will
be difficult to see during the day.
Mounting
Platform
Figure 2-9
Installing the Star Pointer
1.
Before using the StarPointer, you must first remove the protective plastic cover over the battery (see figure 2-10).
2.
To turn on the Star Pointer, rotate the variable brightness control (see figure 2-8) clockwise until you here a "click".
To increase the brightness level of the red dot, continue rotating the control knob about 180º until it stops.
3.
Locate a bright star or planet and center it in a low power eyepiece in the main telescope.
4.
With both eyes open, look through the glass window at the alignment star. If the Star Pointer is perfectly aligned, you will
see the red LED dot overlap the alignment star. If the Star Pointer is not aligned, take notice of where the red dot is
relative to the bright star.
5.
Without moving the main telescope, turn the Star Pointer's azimuth and altitude alignment controls (see figure 2-8) until
the red dot is directly over the alignment object.
9
If the LED dot is brighter than the alignment star, it may make it difficult to see the star. Turn the brightness control
counterclockwise, until the red dot is the same brightness as the alignment star. This will make it easier to get an accurate
alignment. The Star Pointer is now ready to be used.
Protective
Cover
Battery
Red
Alignment
Dot
Azimuth
adjustment
Knob
Figure 2-11
Aligning the StarPointer
Figure 2-10
Battery Compartment
Attaching the Hand Control
The NexStar SLT hand control has a phone jack type connector at the end of its cord. Plug the phone jack connector into the outlet
at the base of the telescope’s fork arm. Push the connector into the outlet until it clicks into place and place the hand control into its
holder as described previously in the Assembly section of the manual.
Auxiliary Port
ON/Off Switch
Hand
Control Port
12 V Power
Outlet
Figure 2-12
The NexStar SLT Outlets
Powering the NexStar
The NexStar SLT can be powered by 8 user supplied AA size alkaline batteries or an optional 12 V AC adapter. To install batteries
into the NexStar:
1.
2.
3.
4.
Squeeze the tabs on both sides of the battery compartment cover while lifting
upward.
Insert 8 AA batteries in to battery compartment holders.
Place the battery compartment cover over the batteries and push down until the
cover snaps in place.
Flip the power switch to the “On” position. The light on the power button should
come on.
In case of a loss of power, the optical tube can be moved by hand. However, when
powered on, the telescope should always be controlled via the hand control.
The NexStar will lose its star alignment if moved by hand when powered on.
10
Figure 2-13
Removing the Battery Compartment
Cover
The Hand Control
The NexStar SLT's hand controller is designed to give you instant access to all the functions the NexStar has to offer.
With automatic slewing to over 4,000 objects, and common sense menu descriptions, even a beginner can master its
variety of features in just a few observing sessions. Below is a brief description of the individual components of the
NexStar SLT hand controller:
1.
2.
3.
4.
Liquid Crystal Display (LCD) Window: Has a dual-line, 16 character display screen that is backlit for comfortable
viewing of telescope information and scrolling text.
Align: Instructs the NexStar to use a selected star or object as an alignment position.
Direction Keys: Allows complete control of the NexStar in any direction. Use the direction keys to center objects in
the StarPointer finderscope and eyepiece.
Catalog Keys: The NexStar has a key on the hand control to allow direct access to each of the catalogs in its 4,000+
object database. The NexStar contains the following catalogs in its database:
Messier – Complete list of all Messier objects.
NGC – Many of the brightest deep sky objects from the Revised New General Catalog.
Caldwell – A combination of the best NGC and IC objects.
Planets – All 8 planets in our Solar System plus the Moon and Sun.
Stars – A compiled list of the brightest stars from the SAO catalog.
List – For quick access, all of the best and most popular objects in the NexStar database have been
broken down into lists based on their type and/or common name:
Named Stars
Named Objects
Double Stars
Variable Stars
Asterisms
Common name listing of the brightest stars in the sky.
Alphabetical listing of over 50 of the most popular deep sky objects.
Alphabetical listing of the most visually stunning double, triple and
quadruple stars in the sky.
Select list of the brightest variable stars with the shortest period of
changing magnitude.
A unique list of some of the most recognizable star patterns in the sky.
11
1
7
2
8
3
9
10
4
5
11
6
12
Figure 3-1
The NexStar Hand Control
5.
6.
Info: Displays coordinates and useful information about objects selected from the NexStar database.
Tour: Activates the tour mode, which seeks out all the best objects for a given month and automatically slews the
NexStar to those objects.
7. Enter: Pressing Enter allows you to select any of the NexStar functions, accept entered parameters and slew the
telescope to displayed objects.
8. Undo: Undo will take you out of the current menu and display the previous level of the menu path. Press Undo
repeatedly to get back to a main menu or use it to erase data entered by mistake.
9. Menu: Displays the many setup and utilities functions such as tracking rate and user defined objects and many
others.
10. Scroll Keys: Used to scroll up and down within any of the menu lists. A double arrow symbol on the right side of
the LCD indicates that the scroll keys can be used to view additional information.
11. Rate: Instantly changes the rate of speed of the motors when the direction buttons are pressed.
12. RS-232 Jack: Allows use with a computer and software programs for point and click slewing capability.
Hand Control Operation
This section describes the basic hand control procedures needed to operate the NexStar. These procedures are grouped
into three categories: Alignment, Setup and Utilities. The alignment section deals with the initial telescope alignment as
well as finding objects in the sky; the setup section discusses changing parameters such as tracking mode and tracking
rate; finally, the last section reviews all of the utility functions such as adjusting the telescopes slew limits and backlash
compensation.
12
Alignment Procedure
In order for the NexStar to accurately point to objects in the sky, it must first be aligned to known positions (stars) in
the sky. With this information, the telescope can create a model of the sky, which it uses to locate any object with
known coordinates. There are many ways to align the NexStar with the sky depending on what information the user
is able to provide: SkyAlign uses your current date, time and city to create an accurate model of the sky. Then the
user can simply point the telescope to any three bright celestial objects to accurately align the telescope with the sky.
Auto Two-Star Align will ask the user to choose and center the first alignment star, then the NexStar will
automatically select and slew to a second star for alignment. Two-Star Alignment requires the user to identify and
manually slew the telescope to the two alignment stars. One-Star Align is the same as Two-Star Align however only
requires you to align to one known star. Although not as accurate as the other alignment methods, One-Star Align is
the quickest way to find and track bright planets and objects in Altazimuth mode. Finally, Solar System Align will
display a list of visible daytime objects (planets and the moon) available to align the telescope. Each alignment
method is discussed in detail below.
Definition
"Altazimuth" or "Alt-Az" refers to a type of mounting that allows a telescope to move in both altitude (up and down)
and azimuth (left and right) with respect to the ground. This is the simplest form of mounting in which the telescope
is attached directly to a tripod.
Sky Align
Sky Align is the easiest way to get your NexStar aligned and ready to observe. Even if you do not know a single star
in the sky, the NexStar will have you aligned in minutes by asking for basic information like the date, time and
location. Then you simply need to aim the telescope to any three bright celestial objects in the sky. Since Sky Align
requires no knowledge of the night sky it is not necessary to know the name of the stars at which you are aiming.
You may even select a planet or the moon. The NexStar is then ready to start finding and tracking any of the objects
in its 4,000+ object database. Before the telescope is ready to be aligned, it should be set up in an outside location
with all accessories (eyepiece, diagonal and finderscope) attached and lens cover removed as described in the
Assembly section of the manual. To begin Sky Align:
1.
Power on the NexStar by flipping the switch located on the side of the fork arm, to the "on" position. Once
turned on the hand control display will say NexStar SLT. Press ENTER to choose Sky Align. Pressing the
ALIGN key will bypass the other alignment options and the scrolling text and automatically begins Sky Align.
2.
Once Sky Align has been selected, the hand control will display “Enter if OK”, “Undo to edit” and “Saved Site”.
The bottom line of the LCD will display either the current time or the time when you last used the telescope.
Since this is your first time using the NexStar, press UNDO to enter current time/site information.
The hand control display will then ask for the following information:
Location - The NexStar will display a list of cities to choose from. Choose the city from the database that is closest to
your current observing site. The city you choose will be remembered in the hand controls memory so that
it will be automatically displayed the next time an alignment is done. Alternatively, if you know the exact
longitude and latitude of your observing site, it can be entered directly into the hand control and
remembered for future use as well. To choose a location city:
Use the Up and Down scroll keys to choose between City Database and Custom Site. City Database will allow
you to select the closest city to your observing site from a list of either international or U.S. location. Custom Site
allows you to enter the exact longitude and latitude of your observing site. Select City Database and press
ENTER.
The hand control will allow you to choose from either U.S. or international locations. For a listing of U.S.
locations by state and then by city, press ENTER while United States is displayed. For international locations,
use the Up or Down scroll key to select International and press ENTER.
Use the Up and Down Scroll buttons to choose your current state (or country if International locations was
selected) from the alphabetical listing and press ENTER.
Use the Up and Down Scroll buttons to choose the closest city to your location from the displayed list and press
ENTER.
13
Time -
Enter the current time for your area. You can enter either the local time (i.e. 8:00), or you can enter
military time (i.e. 20:00).
Select PM or AM. If military time was entered, the hand control will bypass this step.
Choose between Standard time or Daylight Savings time. Use the Up and Down scroll buttons (10) to toggle
between options.
Select the time zone that you are observing from. Again, use the Up and Down buttons (10) to scroll through
the choices. For time zone information, refer to the Time Zone map in the appendix of this manual.
Date - Enter the month, day and year of your observing session. The display will read: mm/dd/yy.
y
If the wrong information has been input into the hand control, the UNDO button will act as a backspace
allowing the user to re-enter information.
y
The next time that your NexStar is aligned, the hand control will automatically display the last location
(either a city or longitude/latitude) that was entered. Press ENTER to accept these parameters if they still
apply. Pressing the UNDO button will allow you to go back and select a new city location or
longitude/latitude.
3.
Use the arrow buttons on the hand control to slew (move) the telescope towards any bright celestial object in
the sky. Align the object with the red dot of the finderscope and press ENTER.
4.
If the finderscope has been properly aligned with the telescope tube, the alignment star should now be
visible inside the field of view of the eyepiece. The hand control will ask that you center the bright
alignment star in the center of the eyepiece and press the ALIGN button. This will accept the star as the first
alignment position. (There is no need to adjust the slewing rate of the motors after each alignment step.
The NexStar automatically selects the best slewing rate for aligning objects in both the finderscope and the
eyepiece).
5.
For the second alignment object, choose a bright star or planet as far as possible from the first alignment
object. Once again use the arrow button to center the object in the finderscope and press ENTER.
Then once centered in the eyepiece press the ALIGN button.
6.
Repeat the process for the third alignment star. When the telescope has been aligned to the final stars, the
display will read "Match Confirmed". Press UNDO to display the names of the three bright objects
you aligned to, or press ENTER to accept these three objects for alignment. You are now ready to find your
first object.
Helpful
Hints
Tips for Using Sky Align
Remember the following alignment guidelines to make using Sky Align as simple and accurate as possible.
y
Be sure to level the tripod before you begin alignment. The time/site information along with a level
tripod will help the telescope better predict the available bright stars and planets that are above the horizon.
y
Remember to select alignment stars that are as far apart in the sky as possible. For best results make sure
that the third alignment star does not lie in a straight line between the first two stars. This may result in a
failed alignment.
y
Don’t worry about confusing planets for stars when selecting alignment objects. SkyAlign works with the
four brightest planets (Venus, Jupiter, Saturn and Mars) as well as the Moon. In addition to the planets, the
hand control has over 80 bright alignment stars to choose from (down to 2.5 magnitude).
y
Rarely SkyAlign will not be able to determine what three alignment objects were centered. This sometimes
happens when a bright planet or the Moon passes near one of the brighter stars. In situations like these it is
best to try to avoid aligning to either object if possible.
y
Be sure to center the objects with the same final movements as the direction of the GoTo Approach.
For example, if the scope normally finishes a GoTo with the front of the scope moving right and up, you
should center all three alignment objects in the eyepiece using the right and up arrow buttons (the up/down
arrows reverse at slew rates of 6 or lower). Approaching the star from this direction when looking through
the eyepiece will eliminate much of the backlash between the gears and assure the most accurate alignment
possible.
14
Auto Two-Star Align
As with Sky Align, Auto Two-Star Align requires you to enter all the necessary time/site information as before. Once this
information is entered, NexStar will prompt you to select and point the telescope at one known star in the sky.
The NexStar now has all the information it needs to automatically choose a second star that will assure the best possible
alignment. Once selected the telescope will automatically slew to that second alignment star to complete the alignment.
With the NexStar set up outside with all accessories attached and the tripod leveled, follow the steps below to align the
telescope:
1.
2.
3.
4.
5.
6.
Once the NexStar is powered on, Press ENTER to begin alignment.
Use the Up and Down scroll keys (10) to select Auto Two-Star Align and press ENTER.
The hand control will display the last time and location information that was entered into the hand control. Use the Up
and Down buttons to scroll through the information. Press ENTER to accept the current information or press UNDO
to manually edit the information (see Sky Align section for detailed instruction on entering time/site information).
The display will now prompt you to select a bright star from the displayed list on the hand control. Use Up and Down
buttons (6 and 9 on the keypad) to scroll to the desired star and then press ENTER.
Use the arrow buttons to slew the telescope to the star you selected. Center the star in the finderscope and press
ENTER. Finally, center the star in the eyepiece and press ALIGN.
Based on this information, the NexStar will automatically display the most suitable second alignment star that is
above the horizon. Press ENTER to automatically slew the telescope to the displayed star. If for some reason you do
not wish to select this star (perhaps it is behind a tree or building), you can either:
y
y
Press the UNDO button to display the next most suitable star for alignment.
Use the UP and DOWN scroll buttons to manually select any star you wish from the entire list of available stars.
Once finished slewing, the display will ask you to use the arrow buttons to align the selected star with the red dot of the
finderscope. Once centered in the finder, press ENTER. The display will then instruct you to center the star in the field of
view of the eyepiece. When the star is centered, press ALIGN to accept this star as your second alignment star. When the
telescope has been aligned to both stars the display will read Align Success, and you are now ready to find your first
object.
Two Star Alignment
With the two-star alignment method, the NexStar requires the user to know the positions of two bright stars in order to
accurately align the telescope with the sky and begin finding objects. Here is an overview of the two-star alignment
procedure:
1.
2.
3.
4.
5.
Once the NexStar is powered on, use the Up and Down scroll keys (10) to select Two-Star Align, and press ENTER.
Press ENTER to accept the time/site information displayed on the display, or press UNDO to enter new information.
The SELECT STAR 1 message will appear in the top row of the display. Use the Up and Down scroll keys (10) to
select the star you wish to use for the first alignment star. Press ENTER.
NexStar then asks you to center in the eyepiece the alignment star you selected. Use the direction arrow buttons to
slew the telescope to the alignment star and carefully center the star in the finderscope. Press ENTER when centered.
Then, center the star in the eyepiece and press ALIGN.
In order to accurately center the alignment star in the eyepiece, you may wish to decrease the slew rate of the motors
for fine centering. This is done by pressing the RATE key (11) on the hand controller then selecting the number that
corresponds to the speed you desire. (9 = fastest, 1 = slowest).
Helpful
Hint
6.
NexStar will then ask you to select and center a second alignment star and press the ALIGN key. It is best to choose
alignment stars that are a good distance away from one another. Stars that are at least 40º to 60º apart from each other
will give you a more accurate alignment than stars that are close to each other.
Once the second star alignment is completed properly, the display will read Align Successful, and you should hear
the tracking motors turn-on and begin to track.
15
One-Star Align
One-Star Align requires you to input all the same information as you would for the Two-Star Align procedure. However,
instead of slewing to two alignment stars for centering and alignment, the NexStar uses only one star to model the sky
based on the information given. This will allow you to roughly slew to the coordinates of bright objects like the moon and
planets and gives the NexStar the information needed to track objects in altazimuth in any part of the sky. One-Star Align
is not meant to be used to accurately locate small or faint deep-sky objects or to track objects accurately for photography.
To use One-Star Align:
1.
Select One-Star Align from the alignment options.
2.
Press ENTER to accept the time/site information displayed on the display, or press UNDO to enter new information.
3.
The SELECT STAR 1 message will appear in the top row of the display. Use the Up and Down scroll keys (10) to
select the star you wish to use for the first alignment star. Press ENTER.
4.
NexStar then asks you to center in the eyepiece the alignment star you selected. Use the direction arrow buttons to
slew the telescope to the alignment star and carefully center the star in the finderscope. Press ENTER when centered.
5.
Then, center the star in the eyepiece and press ALIGN.
6.
Once in position, the NexStar will model the sky based on this information and display Align Successful.
Note: Once a One-Star Alignment has been done, you can use the Re-alignment feature (later in this section ) to improve
your telescope’s pointing accuracy.
Solar System Align
Solar System Align is designed to provide excellent tracking and GoTo performance by using solar system objects
(Sun, Moon and planets) to align the telescope with the sky. Solar System Align is a great way to align your telescope for
daytime viewing as well as a quick way to align the telescope for night time observing.
Never look directly at the sun with the naked eye or with a telescope (unless you have the proper solar filter).
Permanent and irreversible eye damage may result.
1.
2.
3.
4.
5.
Select Solar System Align from the alignment options.
Press ENTER to accept the time/site information displayed on the display, or press UNDO to enter new information.
The SELECT OBJECT message will appear in the top row of the display. Use the Up and Down scroll keys (10) to
select the daytime object (planet, moon or sun) you wish to align. Press ENTER.
NexStar then asks you to center in the eyepiece the alignment object you selected. Use the direction arrow buttons to
slew the telescope to the alignment object and carefully center it in the finderscope. Press ENTER when centered.
Then, center the object in the eyepiece and press ALIGN.
Once in position, the NexStar will model the sky based on this information and display Align Successful.
Tips for Using Solar System Align
y
For safety purposes, the Sun will not be displayed in any of the hand control’s customer object lists unless it is
enabled from the Utilities Menu. To allow the Sun to be displayed on the hand control, do the following:
1.
Press the UNDO button until the display reads “NexStar SLT”
2.
Press the MENU button and use the Up and Down keys to select the Utilities menu. Press ENTER.
3.
Use the UP and Down keys to select Sun Menu and press ENTER.
4.
Press ENTER again to allow the Sun to appear on the hand control display.
The Sun can be removed from the display by using the same procedure as above.
To improve the telescope pointing accuracy, you can use the Re-Align feature as described below.
16
NexStar Re-Alignment
The NexStar has a re-alignment feature which allows you to replace either of the original alignment stars with a new star
or celestial object. This can be useful in several situations:
y
y
If you are observing over a period of a few hours, you may notice that your original two alignment stars have drifted
towards the west considerably. (Remember that the stars are moving at a rate of 15º every hour). Aligning on a new star
that is in the eastern part of the sky will improve your pointing accuracy, especially on objects in that part of the sky.
If you have aligned your telescope using the One-star align method, you can use re-align to align to an additional
object in the sky. This will improve the pointing accuracy of your telescope without having to re-enter addition
information.
To replace an existing alignment star with a new alignment star:
1.
2.
3.
4.
5.
6.
7.
Select the desired star (or object) from the database and slew to it.
Carefully center the object in the eyepiece.
Once centered, press the UNDO button until you are at the main menu.
With NexStar SLT displayed, press the ALIGN key on the hand control.
The display will then ask you which alignment star you want to replace.
Use the UP and Down scroll keys to select the alignment star to be replaced, and press ENTER. It is usually best to
replace the star closest to the new object. This will space out your alignment stars across the sky. If you have used one
of the single object alignment methods then it is always best to replace the object that is “unassigned” with an actual
object.
Press ALIGN to make the change.
Object Catalog
Selecting an Object
Now that the telescope is properly aligned, you can choose an object from any of the catalogs in the NexStar’s database.
The hand control has a key designated for each of the catalogs in its database. There are two ways to select objects from
the database; scrolling through the named object lists and entering object numbers:
y
Pressing the LIST key on the hand control will access all objects in the database that have common names or types.
Each list is broken down into the following categories: Named Stars, Named Object, Double Stars, Variable Stars and
Asterisms. Selecting any one of these options will display an alpha-numeric listing of the objects under that list.
Pressing the Up and Down keys (10) allows you to scroll through the catalog to the desired object.
y
Pressing any of the catalog keys (M, CALD, NGC, or STAR) will display a blinking cursor below the name of the
catalog chosen. Use the numeric key pad to enter the number of any object within these standardized catalogs.
For example, to find the Orion Nebula, press the "M" key and enter "042".
y
Pressing the PLANET button will allow you to use the UP and DOWN arrow keys to scroll through and select the
eight planets as well as the moon.
When scrolling through a long list of objects, holding down either the Up or Down key will allow you to scroll through the
catalog at a rapid speed.
When entering the number for a SAO star, you are only required to enter the first four digits of the objects six digit SAO
number. Once the first four digits are entered, the hand control will automatically list all the available SAO objects
beginning with those numbers. This allows you to scroll through only the SAO stars in the database. For example, in
searching for the SAO star 40186 (Capella), the first four digits would be "0401". Entering this number will display the
closest match from the SAO stars available in the database. From there you can scroll down the list and select the desired
object.
17
Slewing to an Object
Once the desired object is displayed on the hand control screen, you have two options:
y
Press the INFO Key. This will give you useful information about the selected object such as magnitude,
constellation and fascinating facts about many of the objects.
y
Press the ENTER Key. This will automatically slew the telescope to the coordinates of the object. While the
telescope is slewing to the object, the user can still access many of the hand control functions (such as displaying
information about the object).
If you slew to an object that is below the horizon, NexStar will notify you by displaying a message reminding you that you
have selected an object outside of your slew limits (see Slew Limits in the Scope Setup section of the manual).
Press UNDO to go back and select a new object. Press ENTER to ignore the message and continue the slew. The NexStar
hand control will only display objects that are below the horizon if the Filter Limits are set below 0º in altitude. See Filter
Limits in the Utility Feature section of the manual for more information on setting the filter limits.
Caution: Never slew the telescope when someone is looking into the eyepiece. The telescope can move at fast slew
speeds and may hit an observer in the eye.
Object information can be obtained without having to do a star alignment. After the telescope is powered on, pressing any
of the catalog keys allows you to scroll through object lists or enter catalog numbers and view the information about the
object as described above.
Finding Planets
The NexStar can locate all 8 of our solar systems planets plus the Sun and Moon. However, the hand control will only
display the solar system objects that are above the horizon (or within its filter limits). To locate the planets, press the
PLANET key on the hand control. The hand control will display all solar system objects that are above the horizon:
y
y
y
Use the Up and Down keys to select the planet that you wish to observe.
Press INFO to access information on the displayed planet.
Press ENTER to slew to the displayed planet.
To allow the Sun to be displayed as an option in the database, see Sun Menu in the Utilities section of the manual.
Tour Mode
The NexStar includes a tour feature which automatically allows the user to choose from a list of interesting objects based
on the date and time in which you are observing. The automatic tour will display only those objects that are within your set
filter limits. To activate the Tour mode, press the TOUR key on the hand control. The NexStar will display the best objects
to observe that are currently in the sky.
y
y
y
To see information and data about the displayed object, press the INFO key.
To slew to the object displayed, press ENTER.
To see the next tour object, press the Down key.
Constellation Tour
In addition to the Tour Mode, the NexStar telescope has a Constellation Tour that allows the user to take a tour of all the
best objects within a particular constellation. Selecting Constellation from the LIST menu will display all the
constellation names that are above the user defined horizon (filter limits). Once a constellation is selected, you can choose
from any of the database object catalogs to produce a list of all the available objects in that constellation.
y
y
y
To see information and data about the displayed object, press the INFO key.
To slew to the object displayed, press ENTER.
To see the next tour object, press the Up key.
18
Direction Buttons
The NexStar has four direction buttons in the center of the hand control which controls the telescope motion in altitude
(up and down) and azimuth (left and right). The telescope can be controlled at nine different speed rates.
1
2
3
4
5
=
=
=
=
=
2x
4x
8x
16x
32x
6
7
8
9
=
=
=
=
64x
1º / sec
2º / sec
3º / sec
Nine available slew speeds
Rate Button
Pressing the RATE key (11) allows you to instantly change the speed rate of the motors from high speed slew rate to
precise guiding rate or anywhere in between. Each rate corresponds to a number on the hand controller key pad.
The number 9 is the fastest rate (approximately 4º per second, depending on power source) and is used for slewing
between objects and locating alignment stars. The number 1 on the hand control is the slowest rate (2x sidereal) and can
be used for accurate centering of objects in the eyepiece. To change the speed rate of the motors:
y
y
Press the RATE key on the hand control. The LCD will display the current speed rate.
Press the number on the hand control that corresponds to the desired speed.
The hand control has a "double button" feature that allows you to instantly speed up the motors without having to choose a
speed rate. To use this feature, simply press the arrow button that corresponds to the direction that you want to move the
telescope. While holding that button down, press the opposite directional button. This will increase the speed to the
maximum slew rate.
When using the Up and Down buttons on the NexStar 60 and 80, the slower slew rates (6 and lower) move the motors in
the opposite direction than the faster slew rates (7- 9). This is done so that an object will move in the appropriate direction
when looking into the eyepiece (i.e. pressing the up arrow button will move the star upwards in the field of view of the
eyepiece). However, if any of the slower slew rates (rate 6 and below) are used to center an object in the Star Pointer, you
may need to press the opposite directional button to make the telescope move in the correct direction.
Set Up Procedures
The NexStar contains many user defined setup functions designed to give the user control over the telescope's many
advanced features. All of the set up and utility features can be accessed by pressing the MENU key and scrolling through
the options:
Tracking Mode - Once the NexStar is aligned the tracking motors will automatically turn on and begin tracking the
sky. However, the tracking can be turned off for terrestrial use:
Note:
Alt-Az
This is the default tracking rate and is used when the telescope has been
properly aligned.
EQ North
Used to track the sky when the telescope is polar aligned using an equatorial
wedge in the Northern Hemisphere.
EQ South
Used to track the sky when the telescope is polar aligned using an equatorial
wedge in the Southern Hemisphere.
Off
When using the telescope for terrestrial (land) observation the tracking can
be turned off so that the telescope never moves.
EQ North and EQ South tracking modes are only needed with telescopes that can be polar aligned.
The NexStar SLT series are exclusively Alt-Az mounted telescopes and do not require equatorial tracking.
19
Tracking Rate - In addition to being able to move the telescope with the hand control buttons, the NexStar will
continually track a celestial object as it moves across the night sky. The tracking rate can be changed depending on what
type of object is being observed:
Sidereal
This rate compensates for the rotation of the earth by moving the telescope at
the same rate as the rotation of the earth, but in the opposite direction. When
tracking in Alt-Az mode, the telescope must make corrections in both altitude
and azimuth.
Lunar
Used for tracking the moon when observing the lunar landscape.
Solar
Used for tracking the Sun when solar observing using a proper solar filter.
View Time-Site - View Time-Site will display the last saved time and longitude/latitude entered in the hand control.
User Defined Objects:
The NexStar can store up to 50 different user defined objects in its memory.
The objects can be daytime land objects or an interesting celestial object that you
discover that is not included in the regular database. There are several ways to
save an object to memory depending on what type of object it is:
Save Sky Object:
The NexStar stores celestial objects to its database by saving its right ascension
and declination in the sky. This way the same object can be found each time the
telescope is aligned. Once a desired object is centered in the eyepiece, simply
scroll to the "Save Sky Obj" command and press ENTER. The display will
ask you to enter a number between 1-25 to identify the object. Press ENTER
again to save this object to the database.
Save Database (Db)
Object:
This feature allows you to create your own custom tour of database objects by
allowing you to record the current position of the telescope and save the name of
the object by selecting it from any one of the database catalogs. These objects
then can be accessed by selecting GoTo Sky Object.
Save Land Object:
The NexStar can also be used as a spotting scope on terrestrial objects. Fixed
land objects can be stored by saving their altitude and azimuth relative to the
location of the telescope at the time of observing. Since these objects are relative
to the location of the telescope, they are only valid for that exact location. To
save land objects, once again center the desired object in the eyepiece. Scroll
down to the "Save Land Obj" command and press ENTER. The display will
ask you to enter a number between 1-25 to identify the object. Press ENTER
again to save this object to the database.
Enter R.A. - Dec:
You can also store a specific set of coordinates for an object just by entering the
R.A. and declination for that object. Scroll to the "Enter RA-DEC"
command and press ENTER. The display will then ask you to enter first the R.A.
and then the declination of the desired object.
GoTo Object:
To go to any of the user defined objects stored in the database, scroll down to
either GoTo Sky Obj or Goto Land Obj and enter the number of the
object you wish to select and press ENTER. NexStar will automatically retrieve
and display the coordinates before slewing to the object.
To replace the contents of any of the user defined objects, simply save a new object using one of the existing
identification numbers; NexStar will replace the previous user defined object with the current one.
Get R.A./DEC. - Displays the right ascension and declination for the current position of the telescope.
Goto R.A./ DEC. - Allows you to input a specific R.A. and declination and slew to it.
20
Identify
Identify Mode will search any of the NexStar database catalogs or lists and display the name and offset distances to
the nearest matching objects. This feature can serve two purposes. First, it can be used to identify an unknown object
in the field of view of your eyepiece. Additionally, Identify Mode can be used to find other celestial objects that are
close to the objects you are currently observing. For example, if your telescope is pointed at the brightest star in the
constellation Lyra, choosing Identify and then searching the Named Star catalog will no doubt return the star Vega as
the star you are observing. However, by selecting Identify and searching by the Named Object or Messier catalogs,
the hand control will let you know that the Ring Nebula (M57) is approximately 6° from your current position.
Searching the Double Star catalog will reveal that Epsilon Lyrae is only 1° away from Vega. To use the Identify
feature:
y
y
y
Press the Menu button and select the Identify option.
Use the Up/Down scroll keys to select the catalog that you would like to search.
Press ENTER to begin the search.
Note: Some of the databases contain thousands of objects, and can therefore take a minute or two to return the
closest object.
Scope Setup Features
Setup Time-Site - Allows the user to customize the NexStar display by changing time and location parameters
(such as time zone and daylight savings).
Anti-backlash – All mechanical gears have a certain amount of backlash or play between the gears. This play is
evident by how long it takes for a star to move in the eyepiece when the hand control arrow buttons are pressed
(especially when changing directions). The NexStar's anti-backlash features allows the user to compensate for
backlash by inputting a value which quickly rewinds the motors just enough to eliminate the play between gears. The
amount of compensation needed depends on the slewing rate selected; the slower the slewing rate the longer it will
take for the star to appear to move in the eyepiece. Therefore, the anti-backlash compensation will have to be set
higher. You will need to experiment with different values; a value between 20 and 50 is usually best for most visual
observing, whereas a higher value may be necessary for photographic guiding. Positive backlash compensation is
applied when the mount changes its direction of movement from backwards to forwards. Similarly, negative backlash
compensation is applied when the mount changes its direction of movement from forwards to backwards. When
tracking is enabled, the mount will be moving in one or both axes in either the positive or negative direction, so
backlash compensation will always be applied when a direction button is released and the direction moved is opposite
to the direction of travel.
To set the anti-backlash value, scroll down to the anti-backlash option and press ENTER. Enter a value from 0-100
for both azimuth and altitude directions and press ENTER after each one to save these values. NexStar will
remember these values and use them each time it is turned on until they are changed.
Slew Limits – Sets the limits in altitude that the telescope can slew without displaying a warning message. The slew
limits prevent the telescope tube from slewing to an object below the horizon or slewing to an object that is high
enough that the tube might hit one of the tripod legs. However, the slew limits can be customized depending on your
needs. For example, if you would like to slew to an object that is close to the zenith and are certain that the tube will
not hit the tripod legs, you can set the slew limits to 90º in altitude. This will allow the telescope to slew to any object
above the horizon without warning.
Observing
Tip!
Filter Limits – When an alignment is complete, the NexStar automatically knows which celestial objects are above
the horizon. As a result, when scrolling through the database lists (or selecting the Tour function), the NexStar hand
control will display only those objects that are known to be above the horizon when you are observing. You can
customize the object database by selecting altitude limits that are appropriate for your location and situation. For
example, if you are observing from a mountainous location where the horizon is partially obscured, you can set your
minimum altitude limit to read +20º. This will make sure that the hand control only displays objects that are higher in
altitude than 20º.
If you want to explore the entire object database, set the maximum altitude limit to 90º and the minimum limit to –90º.
This will display every object in the database lists regardless of whether it is visible in the sky from your location or
not.
21
Direction Buttons – The direction a star moves in the eyepiece varies depending on the accessories being used.
This can create confusion when guiding on a star using an off-axis guider versus a straight through guide scope. To
compensate for this, the direction of the drive control keys can be changed. To reverse the button logic of the hand
control, press the MENU button and select Direction Buttons from the Utilities menu. Use the Up/Down arrow keys
(10) to select either the Azimuth buttons (left and right) or Altitude buttons (up and down) and press ENTER.
Pressing ENTER again will reverse the direction of the hand control buttons from their current state. Direction
Buttons will only change the eyepiece rates (rate 1-6) and will not affect the slew rates (rate 7-9).
Goto Approach – lets the user define the direction that the telescope will approach when slewing to an object. This
allows the user the ability to minimize the effects of backlash For example, if your telescope is back heavy from using
heavy optical or photographic accessories attached to the back, you would want to set your altitude approach to the
negative direction. This would ensure that the telescope always approaches an object from the opposite direction as
the load pulling on the scope.
To change the goto approach direction, simply choose Goto Approach from the Scope Setup menu, select either
Altitude or Azimuth approach, choose positive or negative and press Enter.
Cordwrap – Cord wrap safeguards against the telescope slewing more than 360º in azimuth and wrapping accessory
cables around the base of the telescope. This is useful any time that the telescope is powered using an external power
supply. By default, the cord wrap feature is turned off when the telescope is aligned in altazimuth and turn on when
aligned on a wedge.
Utility Features
Scrolling through the MENU options will also provide access to several advanced utility functions such as antibacklash compensation and slew limits.
GPS On/Off – This feature is only available when using your telescope in conjunction with the optional CN 16
GPS accessory. Allows you to turn off the GPS module. If you want to use the NexStar database to find the
coordinates of a celestial object for a future date you would need to turn the GPS module off in order to manually
enter a date and time other than the present.
Light Control – This feature allows you to turn off both the red key pad light and LCD display for daytime use to
conserve power and to help preserve your night vision.
Factory Setting – Returns the NexStar hand control to its original factory setting. Parameters such as backlash
compensation values, initial date and time, longitude/latitude along with slew and filter limits will be reset. However,
stored parameters such as PEC and user defined objects will remain saved even when Factory Settings is selected.
The hand control will ask you to press the "0" key before returning to the factory default setting.
Version – Selecting this option will allow you to see the current version number of the hand control and motor
control software. The first set of numbers indicate the hand control software version. For the motor control, the hand
control will display two sets of numbers; the first numbers are for azimuth and the second set are for altitude.
Get Axis Position – Displays the relative altitude and azimuth for the current position of the telescope.
Goto Axis Position – Allows you to enter a specific altitude and azimuth position and slew to it.
Hibernate – Hibernate allows the NexStar to be completely powered down and still retain its alignment when turned
back on. This not only saves power, but is ideal for those that have their telescopes permanently mounted or leave
their telescope in one location for long periods of time. To place your telescope in Hibernate mode:
Helpful
Hint
1.
2.
3.
Select Hibernate from the Utility Menu.
Move the telescope to a desire position and press ENTER.
Power off the telescope. Remember to never move your telescope manually while in Hibernate mode.
Once the telescope is powered on again the display will read Wake Up. After pressing Enter you have the option of
scrolling through the time/site information to confirm the current setting. Press ENTER to wake up the telescope.
Pressing UNDO at the Wake Up screen allows you to explore many of the features of the hand control without
waking the telescope up from hibernate mode. To wake up the telescope after UNDO has been pressed, select
Hibernate from the Utility menu and press ENTER. Do not use the direction buttons to move the telescope while in
hibernate mode.
22
Sun Menu
For safety purposes the Sun will not be displayed as a database object unless it is first enabled. The enable the Sun, go
to the Sun Menu and press ENTER. The Sun will now be displayed in the Planets catalog as can be used as an
alignment object when using the Solar System Alignment method. To remove the Sun from displaying on the hand
control, once again select the Sun Menu from the Utilities Menu and press ENTER.
Scrolling Menu
This menu allows you to change the rate of speed that the text scrolls across the hand control display.
y
y
Press the Up (number 6) button to increase the speed of the text.
Press the Down (number 9) button to decrease the speed of the text.
Calibrate Goto
Goto Calibration is a useful tool when attaching heavy visual or photographic accessories to the telescope. Goto
Calibration calculates the amount of distance and time it takes for the mount to complete its final slow goto when
slewing to an object. Changing the balance of the telescope can prolong the time it takes to complete the final slew.
Goto Calibration takes into account any slight imbalances and changes the final goto distance to compensate.
Set Mount Position
The Set Mount Position menu can be used to recover an alignment in cases where the telescope or tripod has been
manually moved. For instance, you might use this feature if you needed to adjust the level of the tripod by raising or
lowering the tripod legs. After the mount has been moved, simply slew to a bright star and center it up in the
eyepiece, then select Set Mount Position from the Utilities menu. Since the telescope has been moved, the pointing
accuracy will be diminished. But now you can slew to a new set of alignment stars and replace any of the original
alignment stars with the new stars. This will help you to avoid having to start the alignment process over from the
beginning.
23
NexStar SLT
MENU
TRACKING
MODE
ALT-AZ
EQ NORTH
EQ SOUTH
OFF
RATE
SIDEREAL
SOLAR
LUNAR
VIEW TIME-SITE
SCOPE SETUP
SETUP TIME-SITE
ANTI-BACKLASH
SLEW LIMITS
FILTER LIMITS
DIRECTION BUTTONS
GOTO APPROACH
CORDWRAP
UTILITIES
GPS ON/OFF
LIGHT CONTROL
FACTORY SETTING
VERSION
GET ALT-AZ
GOTO ALT-AZ
HIBERNATE
SUN MENU
SCROLLING MENU
USER OBJECTS
GOTO SKY OBJ
SAVE SKY OBJ
SAVE DB OBJ
ENTER RA & DEC
SAVE LAND OBJ
GOTO LAND OBJ
GET RA-DEC
GOTO RA-DEC
INDENTIFY
SELECT CATALOG
ALIGNMENT
LIST
SKY ALIGN
Saved Site
ENTER if OK
UNDO to Edit
Center Alignment Object 1
Center Alignment Object 2
Center Alignment Object 3
AUTO TWO-STAR ALIGN
Saved Site
ENTER if OK
UNDO to Edit
NAMED STAR
NAMED OBJECT
ASTERISM
TOUR
VARIABLE STAR
DOUBLE STAR
CCD OBJECTS
ABELL
IC CATALOG
CALDWELL
MESSIER
NGC
SAO
SOLAR SYSTEM
CONSTELLATION
Select Star 1
Center Star 1
Center Star 2
TWO-STAR ALIGNMENT
Saved Site
ENTER if OK
UNDO to Edit
SELECT STAR 1
CENTER STAR 1
SELECT STAR 2
CENTER STAR 2
ONE-STAR ALIGNMENT
Saved Site
ENTER if OK
UNDO to Edit
Select Star 1
Center Star 1
SOLAR SYSTEM ALIGN
Saved Site
ENTER if OK
UNDO to Edit
Select Object
Center Object
NexStar Menu Tree:
The above figure is a menu tree showing the sub-menus associated with the primary command functions
24
A telescope is an instrument that collects and focuses light. The nature of the optical design determines how the light is
focused. Some telescopes, known as refractors, use lenses. Other telescopes, known as reflectors, use mirrors.
The Maksutov-Cassegrain optical system uses a combination of mirrors and lenses and is referred to as a compound or
catadioptric telescope. This unique design offers large-diameter optics while maintaining very short tube lengths, making
them extremely portable. The Maksutov-Cassegrain system consists of a corrector plate, a spherical primary mirror, and a
secondary mirror spot. Once light rays enter the optical system, they travel the length of the optical tube three times.
FOCAL PLANE
MAKSUTOV
CORRECTOR
INCOMING
LIGHT
PRIMARY
MIRROR
SECONDARY
SPOT
INCOMING
LIGHT
Focusing
Once you have found an object in the telescope, turn the focusing knob until the image is sharp. To focus on an object that
is nearer than your current target, turn the focusing knob toward the eyepiece (i.e., so that the focusing tube moves away
from the front of the telescope). For more distant objects, turn the focusing knob in the opposite direction. To achieve a
truly sharp focus, never look through glass windows or across objects that produce heat waves, such as asphalt parking
lots.
For astronomical viewing, out of focus star images are very diffuse, making them difficult to see. If you turn the focus
knob too quickly, you can go right through focus without seeing the image. To avoid this problem, your first astronomical
target should be a bright object (like the Moon or a planet) so that the image is visible even when out of focus.
Image Orientation
The image orientation of any telescope changes depending on how the eyepiece is inserted into the telescope. When
observing through the using the diagonal, the image will be right side up, but reversed from left to right. When observing
straight through, with the eyepiece inserted directly into the telescope, the image will be inverted.
Inverted image, as viewed with
the eyepiece directly in telescope
Reversed from left to right, as
viewed with a Star Diagonal
25
Calculating Magnification
You can change the power of your telescope just by changing the eyepiece (ocular). To determine the magnification of
your telescope, simply divide the focal length of the telescope by the focal length of the eyepiece used. In equation
format, the formula looks like this:
Magnification =
Focal Length of Telescope (mm)
Focal Length of Eyepiece (mm)
Let’s say, for example, you are using the 25mm eyepiece. To determine the magnification you simply divide the focal
length of your telescope (for example, the NexStar 127 has a focal length of 1500mm) by the focal length of the eyepiece,
25mm. Dividing 1500 by 25 yields a magnification of 60 power.
Although the power is variable, each instrument under average skies has a limit to the highest useful magnification.
The general rule is that 60 power can be used for every inch of aperture. For example, the NexStar 127 is 5” (127mm) in
diameter. Multiplying 5 by 60 gives a maximum useful magnification of 300 power. Although this is the maximum
useful magnification, most observing is done in the range of 20 to 35 power for every inch of aperture which is 100 to 175
times for the NexStar 127 telescope.
Determining Field of View
Determining the field of view is important if you want to get an idea of the angular size of the object you are observing.
To calculate the actual field of view, divide the apparent field of the eyepiece (supplied by the eyepiece manufacturer) by
the magnification. In equation format, the formula looks like this:
Apparent Field of Eyepiece
True Field =
Magnification
As you can see, before determining the field of view, you must calculate the magnification. Using the example in the
previous section, we can determine the field of view using the same 25mm eyepiece. The 25mm eyepiece has an apparent
field of view of 50°. Divide the 50° by the magnification, which is 60 power. This yields an actual field of view of .83°.
To convert degrees to feet at 1,000 yards, which is more useful for terrestrial observing, simply multiply by 52.5.
Continuing with our example, multiply the angular field .83° by 52.5. This produces a linear field width of 44 feet at a
distance of one thousand yards. The apparent field of each eyepiece that Celestron manufactures is found in the Celestron
Accessory Catalog (#93685).
General Observing Hints
When working with any optical instrument, there are a few things to remember to ensure you get the best possible image:
y
Never look through window glass. Glass found in household windows is optically imperfect, and as a result, may
vary in thickness from one part of a window to the next. This inconsistency can and will affect the ability to focus
your telescope. In most cases you will not be able to achieve a truly sharp image, while in some cases, you may
actually see a double image.
y
Never look across or over objects that are producing heat waves. This includes asphalt parking lots on hot summer
days or building rooftops.
y
Hazy skies, fog, and mist can also make it difficult to focus when viewing terrestrially. The amount of detail seen
under these conditions is greatly reduced. Also, when photographing under these conditions, the processed film may
come out a little grainier than normal with lower contrast and underexposed.
y
If you wear corrective lenses (specifically glasses), you may want to remove them when observing with an eyepiece
attached to the telescope. When using a camera, however, you should always wear corrective lenses to ensure the
sharpest possible focus. If you have astigmatism, corrective lenses must be worn at all times.
26
With your telescope set up, you are ready to use it for observing. This section covers visual observing hints for both
solar system and deep sky objects as well as general observing conditions which will affect your ability to observe.
Observing the Moon
Often, it is tempting to look at the Moon when it is full. At this time,
the face we see is fully illuminated and its light can be overpowering.
In addition, little or no contrast can be seen during this phase.
One of the best times to observe the Moon is during its partial phases
(around the time of first or third quarter). Long shadows reveal a great
amount of detail on the lunar surface. At low power you will be able
to see most of the lunar disk at one time. Change to higher power
(magnification) to focus in on a smaller area. Choose the lunar
tracking rate from the NexStar's MENU tracking rate options to keep
the moon centered in the eyepiece even at high magnifications.
Lunar Observing Hints
y
To increase contrast and bring out detail on the lunar surface, use eyepiece filters. A yellow filter works well at
improving contrast while a neutral density or polarizing filter will reduce overall surface brightness and glare.
Observing the Planets
Other fascinating targets include the five naked eye planets. You can see Venus go
through its lunar-like phases. Mars can reveal a host of surface detail and one, if
not both, of its polar caps. You will be able to see the cloud belts of Jupiter and
the great Red Spot (if it is visible at the time you are observing). In addition, you
will also be able to see the moons of Jupiter as they orbit the giant planet. Saturn,
with its beautiful rings, is easily visible at moderate power.
Planetary Observing Hints
y
y
Remember that atmospheric conditions are usually the limiting factor on how much planetary detail will be
visible. So, avoid observing the planets when they are low on the horizon or when they are directly over a source
of radiating heat, such as a rooftop or chimney. See the "Seeing Conditions" section later in this section.
To increase contrast and bring out detail on the planetary surface, try using Celestron eyepiece filters.
Observing the Sun
Although overlooked by many amateur astronomers, solar observation is both rewarding and fun. However, because
the Sun is so bright, special precautions must be taken when observing our star so as not to damage your eyes or your
telescope.
Never project an image of the Sun through the telescope. Tremendous heat build-up may result inside the
optical tube. This can damage the telescope and/or any accessories attached to the telescope.
27
Solar Observing Hints
y
The best time to observe the Sun is in the early morning or late afternoon when the air is cooler.
y
To center the Sun without looking into the eyepiece, watch the shadow of the telescope tube until it forms a
circular shadow.
y
To ensure accurate tracking on SLT models, be sure to select solar tracking rate.
Observing Deep Sky Objects
Deep sky objects are simply those objects outside the boundaries of our solar system. They include star clusters,
planetary nebulae, diffuse nebulae, double stars and other galaxies outside our own Milky Way. Most deep sky objects
have a large angular size. Therefore, low-to-moderate power is all you need to see them. Visually, they are too faint
to reveal any of the color seen in long exposure photographs. Instead, they appear black and white. And, because of
their low surface brightness, they should be observed from a dark sky location. Light pollution around large urban
areas washes out most nebulae making them difficult, if not impossible, to observe. Light Pollution Reduction filters
help reduce the background sky brightness, thus increasing contrast.
Seeing Conditions
Viewing conditions affect what you can see through your telescope during an observing session. Conditions include
transparency, sky illumination, and seeing. Understanding viewing conditions and the effect they have on observing
will help you get the most out of your telescope.
Transparency
Transparency is the clarity of the atmosphere which is affected by clouds, moisture, and other airborne particles.
Thick cumulus clouds are completely opaque while cirrus can be thin, allowing the light from the brightest stars
through. Hazy skies absorb more light than clear skies making fainter objects harder to see and reducing contrast on
brighter objects. Aerosols ejected into the upper atmosphere from volcanic eruptions also affect transparency. Ideal
conditions are when the night sky is inky black.
Sky Illumination
General sky brightening caused by the Moon, aurorae, natural airglow, and light pollution greatly affect transparency.
While not a problem for the brighter stars and planets, bright skies reduce the contrast of extended nebulae making
them difficult, if not impossible, to see. To maximize your observing, limit deep sky viewing to moonless nights far
from the light polluted skies found around major urban areas. LPR filters enhance deep sky viewing from light
polluted areas by blocking unwanted light while transmitting light from certain deep sky objects. You can, on the
other hand, observe planets and stars from light polluted areas or when the Moon is out.
28
Seeing
Seeing conditions refers to the stability of the atmosphere and directly affects the amount of fine detail seen in
extended objects. The air in our atmosphere acts as a lens which bends and distorts incoming light rays. The
amount of bending depends on air density. Varying temperature layers have different densities and, therefore,
bend light differently. Light rays from the same object arrive slightly displaced creating an imperfect or smeared
image. These atmospheric disturbances vary from time-to-time and place-to-place. The size of the air parcels
compared to your aperture determines the "seeing" quality. Under good seeing conditions, fine detail is visible
on the brighter planets like Jupiter and Mars, and stars are pinpoint images. Under poor seeing conditions,
images are blurred and stars appear as blobs.
The conditions described here apply to both visual and photographic observations.
Figure 5-1
Seeing conditions directly affect image quality. These drawing represent a point source (i.e., star) under
bad seeing conditions (left) to excellent conditions (right). Most often, seeing conditions produce images
that lie some where between these two extremes.
29
While your NexStar telescope requires little maintenance, there are a few things to remember that will ensure your
telescope performs at its best.
Care and Cleaning of the Optics
Occasionally, dust and/or moisture may build up on the lens of your telescope. Special care should be taken when
cleaning any instrument so as not to damage the optics.
If dust has built up on the optics, remove it with a brush (made of camel’s hair) or a can of pressurized air. Spray at an
angle to the lens for approximately two to four seconds. Then, use an optical cleaning solution and white tissue paper to
remove any remaining debris. Apply the solution to the tissue and then apply the tissue paper to the lens. Low pressure
strokes should go from the center of the corrector to the outer portion. Do NOT rub in circles!
You can use a commercially made lens cleaner or mix your own. A good cleaning solution is isopropyl alcohol mixed
with distilled water. The solution should be 60% isopropyl alcohol and 40% distilled water. Or, liquid dish soap diluted
with water (a couple of drops per one quart of water) can be used.
To minimize the need to clean your telescope, replace all lens covers once you have finished using it. This will prevent
contaminants from entering the optical tube.
Collimation
The optical performance of your telescope is directly related to its collimation, that is the alignment of its optical system.
Your telescope was collimated at the factory after it was completely assembled. However, if the telescope is dropped or
jarred severely during transport, it may have to be collimated.
To check the collimation of your telescope you will need a light source. A bright star near the zenith is ideal since there is
a minimal amount of atmospheric distortion. Make sure that tracking is on so that you won’t have to manually track the
star. Or, if you do not want to power up your telescope, you can use Polaris. Its position relative to the celestial pole
means that it moves very little thus eliminating the need to manually track it.
Before you begin the collimation process, be sure that your telescope is in thermal equilibrium with the surroundings.
Allow as much as 45 minutes for the telescope to reach equilibrium if you move it between large temperature extremes.
To verify collimation, view a star near the zenith. Use your high power eyepiece - 9mm focal length. It is important to
center a star in the center of the field to judge collimation. Slowly cross in and out of focus and judge the symmetry of the
star. If you see a systematic skewing of the star to one side, then re-collimation is needed.
Figure 6-1
Even though the star pattern appears the same on both sides of focus, they are asymmetric. The dark obstruction is
skewed off to the left side of the diffraction pattern indicating poor collimation.
30
To collimate your telescope, remove the diagonal and eyepiece and look into rear opening of the tube (also remove the
dust cover from the front of the tube). This can be done indoors, with the telescope pointed at a white wall in a well-lit
room. Try to keep your eye centered with respect to the rear opening of the tube as best as possible. Using a Collimating
Eyepiece will aid greatly in keeping your eye centered and is strongly recommend (see Accessories section).
Front of
telescope
Secondary mirror
Front of
telescope
Reflection of your
eye in Secondary
Secondary mirror
Reflection of
your eye in
secondary
mirror
Secondary
reflection of
inside of tube
Reflection of
inside of tube
(Misalignment)
Figure 6-2
Out of collimation (alignment) optics as seen through the
rear of the telescope.
Figure 6-3
Collimated (aligned) optics as seen through the rear of the
telescope.
Once you are ready to collimate, look into rear opening of the tube. If your telescope is out of collimation, it will resemble
Figure 6-2. A properly collimated scope will resemble Figure 6-3. The direction of the misalignment in your telescope
may differ from Figure 6-2 but the diagram will give you the general idea of how things will look.
Note there are six alignment screws on the back of the optical tube, three large and three small. You will need 3mm and
2mm Allen wrenches to turn these screws. These alignment screws push and pull the mirror cell in order to tilt it. When
you loosen or tighten one of these screws, the other five screws must be adjusted as well to keep the proper amount of
pressure on the back of the mirror cell.
Look into the rear opening of the tube and locate the black crescent that
shows the telescope is out of alignment (Figure 6-2). Note which way the
front of the telescope would need to move in order to “fill” that black
crescent and resemble Figure 6-3 Then look at the back end of the
telescope and locate the alignment screw that is in the direction that the
front of the telescope needs to move. For example, if the view in your
telescope resembled Figure 6-2 then you would want to move the front
opening of the telescope scope to the right. The alignment screw you
would start with would be the screw on the right as shown in Figure 6-4.
Repeat the above steps until the front opening is centered in the direction
you wanted it to go and the view through the rear cell looks like Figure 63. You may need to repeat this process with the other screws in order to
align it in other directions.
"Push"
Collimation
Screws
"Pull"
Collimation
Screws
Figure 6-4
Tips for Collimating
-
If you feel any resistance while turning a screw, stop immediately and loosen the two screws on either side of the one
you are turning.
-
Only make small adjustments to each screw; turning them only ¼ turn at a time.
-
If your telescope appears collimated after star testing, it should not need adjustment again unless it is roughly
handled.
31
You will find that additional accessories enhance your viewing pleasure and expand the usefulness of your telescope.
For ease of reference, all the accessories are listed in alphabetical order.
Adapter, Car Battery (#18778) – Celestron offers the Car Battery Adapter that allows you to run the NexStar drive
off an external power source. The adapter attaches to the cigarette lighter of your car, truck, van, or motorcycle.
Barlow lens, OMNI 1.25" (#93326) – Double the magnification of any of your Celestron eyepieces with this fully
multi-coated, low profile Barlow lens
Collimation Eyepiece- (#94182) – is ideal for precise collimation of Newtonians and helpful for
aligning SCT and MAK telescopes. This special eyepiece fits into 1¼" focusers or diagonals.
Alignment is easy using the small opening on one end and thin cross hairs at the other end.
Erect Image Diagonal (#94112-A) – This accessory is an Amici prism arrangement that allows
you to look into the telescope at a 45° angle with images that are oriented properly (upright and
correct from left-to-right).
Eyepieces – Like telescopes, eyepieces come in a variety of designs. Each design has its own advantages and
disadvantages. For the 1-1/4" barrel diameter there are four different eyepiece designs available:
y
OMNI Plössl – Plössl eyepieces have a 4-element lens designed for low-to-high power
observing. The Plössls offer razor sharp views across the entire field, even at the
edges! In the 1-1/4" barrel diameter, they are available in the following focal lengths:
4mm, 6mm, 9mm, 12.5mm, 15mm, 20mm, 25mm, 32mm and 40mm.
y
X-Cel – This 6 element design allows each X-Cel Eyepiece to have 20mm of eye
relief, 55° field of view and more than 25mm of lens aperture (even with the 2.3mm).
In order to maintain razor sharp, color corrected images across its 50° field of view,
extra-low dispersion glass is used for the most highly curved optical elements. The
excellent refractive properties of these high grade optical elements make the X-Cel
line especially well suited for high magnification planetary viewing where sharp,
color-free views are most appreciated. X-Cel eyepiece come in the following focal
length: 2.3mm, 5mm, 8mm, 10mm, 12.5mm, 18mm, 21mm, 25mm.
The Eyepiece and Filter Kit (#94303) – contains Five Superior Grade Plössl
Eyepieces - 1.25”. Barlow Lens - 2x 1.25”. Six Colored Eyepiece (Lunar &
Planetary) Filters. Moon Filter. Aluminum Carrying Case
Flashlight, Night Vision – (#93588) - Celestron’s premium model for astronomy,
using two red LEDs to preserve night vision better than red filters or other devices.
Brightness is adjustable. Operates on a single 9 volt battery (included).
32
UHC/LPR Filter #94123
Filter, Light Pollution Reduction – UHC/LPR (#94123) – These filters are designed to
enhance your views of deep sky astronomical objects when viewed from urban areas. LPR
Filters selectively reduce the transmission of certain wavelength of light, specifically those
produced by artificial lights. This includes mercury and high and low pressure sodium vapor
lights. In addition, they also block unwanted natural light (sky glow) caused by neutral
oxygen emission in our atmosphere.
PowerTank (#18774) – 12 V 7Amp hour rechargeable power supply. Comes with two 12v output cigarette outlets,
built-in red flash light, Halogen emergency spotlight. AC adapter and cigarette lighter adapter included.
RS-232 Cable (#93920) – Allows your NexStar telescope to be controlled using a laptop computer or PC. Once
connected, the NexStar can be controlled using popular astronomy software programs.
Sky Maps (#93722) – Celestron Sky Maps are the ideal teaching guide for learning
the night sky. You wouldn’t set off on a road trip without a road map, and you
don’t need to try to navigate the night sky without a map either. Even if you
already know your way around the major constellations, these maps can help you
locate all kinds of fascinating objects.
Vibration Suppression Pads (#93503) – These pads rest between the ground and
tripod feet of your telescope. They reduce the amplitude and vibration time of your
telescope when shaken by the wind or an accidental bump.
A full description of all Celestron accessories can be found on our web site at www.celestron.com
33
APPENDIX A - TECHNICAL SPECIFICATIONS
O
S
O
Spppeeeccciiifffiiicccaaatttiiiooonnn
Oppptttiiicccaaalll S
Design
NexStar 90mm
Maksutov-Cassegrain
NexStar 127mm
Maksutov-Cassegrain
Aperture
90mm
127mm
Focal Length
1250mm
1500mm
F/ratio of the Optical System
14
12
Optical Coatings
Fully Coated
Fully Coated
Highest Useful Magnification
213x
300x
Resolution: Rayleigh Criterion
Dawes Limit
1.55 arc seconds
1.29 arc seconds
1.1 arc seconds
.91 arc seconds
Light Gathering Power
165x unaided eye
329x unaided eye
Field of View: Standard Eyepiece
1º
.83º
Linear Field of View (at 1000 yds)
53feet
44 feet
Eyepiece Magnification:
50x (25mm)
139x (9mm)
60x (25mm)
167x (9mm)
Optical Tube Length
10 inches
12 inches
EElleeccttrroonniicc SSppeecciiffiiccaattiioonnss
Input Voltage
12 V DC Nominal
Batteries Required
8 AA Alkaline
Power Supply Requirements
12 VDC-750 mA (Tip positive)
M
Meecchhaanniiccaall SSppeecciiffiiccaattiioonnss
Motor:
Type
Resolution
DC Servo motors with encoders, both axes
.26 arc sec
Slew speeds
Nine slew speeds: 3º /sec, 2º /sec, 1º/sec, .64x, 32x, 16x, 8x, 4x, 2x
Hand Control
Double line, 16 character Liquid Crystal Display
19 fiber optic backlit LED buttons
Fork Arm
Cast aluminum
SSooffttw
waarree SSppeecciiffiiccaattiioonnss
Software Precision
16 bit, 20 arc sec. calculations
Ports
RS-232 communication port on hand control
Tracking Rates
Sidereal, Solar and Lunar
Tracking Modes
Alt-Az, EQ North & EQ South
Alignment Procedures
Sky Align, Auto 2-Star, 2-Star, One-Star, Solar System Align
Database
99 user defined programmable object.
Expanded information on over 200 objects
Total Object Database
4,033 Objects
34
GLOSSARY OF TERMS
AAbsolute magnitude
Airy disk
Alt-Azimuth Mounting
Altitude
Aperture
Apparent Magnitude
Arc minute
Arc second
Asterism
Asteroid
Astrology
Astronomical unit (AU)
Aurora
Azimuth
BBinary Stars
CCelestial Equator
Celestial pole
Celestial Sphere
Collimation
DDeclination (DEC)
EEcliptic
Equatorial mount
FFocal length
G
GoTo
The apparent magnitude that a star would have if it were observed from a standard distance of 10
parsecs, or 32.6 light-years. The absolute magnitude of the Sun is 4.8. at a distance of 10 parsecs, it
would just be visible on Earth on a clear moonless night away from surface light.
The apparent size of a star's disk produced even by a perfect optical system. Since the star can never
be focused perfectly, 84 per cent of the light will concentrate into a single disk, and 16 per cent into
a system of surrounding rings.
A telescope mounting using two independent rotation axes allowing movement of the instrument in
Altitude and Azimuth.
In astronomy, the altitude of a celestial object is its Angular Distance above or below the celestial
horizon.
The diameter of a telescope's primary lens or mirror; the larger the aperture, the greater the
telescope's light-gathering power.
A measure of the relative brightness of a star or other celestial object as perceived by an observer on
Earth.
A unit of angular size equal to 1/60 of a degree.
A unit of angular size equal to 1/3,600 of a degree (or 1/60 of an arc minute).
A small unofficial grouping of stars in the night sky.
A small, rocky body that orbits a star.
The pseudoscientific belief that the positions of stars and planets exert an influence on human
affairs; astrology has nothing in common with astronomy.
The distance between the Earth and the Sun. It is equal to 149,597,900 km., usually rounded off to
150,000,000 km.
The emission of light when charged particles from the solar wind slams into and excites atoms and
molecules in a planet's upper atmosphere.
The angular distance of an object eastwards along the horizon, measured from due north, between
the astronomical meridian (the vertical line passing through the center of the sky and the north and
south points on the horizon) and the vertical line containing the celestial body whose position is to
be measured.
Binary (Double) stars are pairs of stars that, because of their mutual gravitational attraction, orbit
around a common center of mass. If a group of three or more stars revolve around one another, it is
called a multiple system. It is believed that approximately 50 percent of all stars belong to binary or
multiple systems. Systems with individual components that can be seen separately by a telescope are
called visual binaries or visual multiples. The nearest "star" to our solar system, Alpha Centauri, is
actually our nearest example of a multiple star system, it consists of three stars, two very similar to
our Sun and one dim, small, red star orbiting around one another.
The projection of the Earth's equator on to the celestial sphere. It divides the sky into two equal
hemispheres.
The imaginary projection of Earth's rotational axis north or south pole onto the celestial sphere.
An imaginary sphere surrounding the Earth, concentric with the Earth's center.
The act of putting a telescope's optics into perfect alignment.
The angular distance of a celestial body north or south of the celestial equator. It may be said to
correspond to latitude on the surface of the Earth.
The projection of the Earth's orbit on to the celestial sphere. It may also be defined as "the apparent
yearly path of the Sun against the stars".
A telescope mounting in which the instrument is set upon an axis which is parallel to the axis of the
Earth; the angle of the axis must be equal to the observer's latitude.
The distance between a lens (or mirror) and the point at which the image of an object at infinity is
brought to focus. The focal length divided by the aperture of the mirror or lens is termed the focal
ratio.
Term used to refer to a computerized telescope or to the act of slewing (moving) a computerized
telescope.
35
JJovian Planets
KKuiper Belt
LLight-Year (ly)
MMagnitude
Meridian
Messier
NNebula
North Celestial Pole
Nova
OOpen Cluster
PParallax
Parfocal
Parsec
Point Source
RReflector
Resolution
Right Ascension: (RA)
SSidereal Rate
Any of the four gas giant planets that are at a greater distance form the sun than the terrestrial
planets.
A region beyond the orbit of Neptune extending to about 1000 AU which is a source of many short
period comets.
A light-year is the distance light traverses in a vacuum in one year at the speed of 299,792 km/ sec.
With 31,557,600 seconds in a year, the light-year equals a distance of 9.46 X 1012 km (5.87 X 1
trillion mi).
Magnitude is a measure of the brightness of a celestial body. The brightest stars are assigned
magnitude 1 and those increasingly fainter from 2 down to magnitude 5. The faintest star that can be
seen without a telescope is about magnitude 6. Each magnitude step corresponds to a ratio of 2.5 in
brightness. Thus a star of magnitude 1 is 2.5 times brighter than a star of magnitude 2, and 100 times
brighter than a magnitude 5 star. The brightest star, Sirius, has an apparent magnitude of -1.6, the
full moon is -12.7, and the Sun's brightness, expressed on a magnitude scale, is -26.78. The zero
point of the apparent magnitude scale is arbitrary.
A reference line in the sky that starts at the North celestial pole and ends at the South celestial pole
and passes through the zenith. If you are facing South, the meridian starts from your Southern
horizon and passes directly overhead to the North celestial pole.
A French astronomer in the late 1700’s who was primarily looking for comets. Comets are hazy
diffuse objects and so Messier cataloged objects that were not comets to help his search. This
catalog became the Messier Catalog, M1 through M110.
Interstellar cloud of gas and dust. Also refers to any celestial object that has a cloudy appearance.
The point in the Northern hemisphere around which all the stars appear to rotate. This is caused by
the fact that the Earth is rotating on an axis that passes through the North and South celestial poles.
The star Polaris lies less than a degree from this point and is therefore referred to as the "Pole Star".
Although Latin for "new" it denotes a star that suddenly becomes explosively bright at the end of its
life cycle.
One of the groupings of stars that are concentrated along the plane of the Milky Way. Most have an
asymmetrical appearance and are loosely assembled. They contain from a dozen to many hundreds
of stars.
Parallax is the difference in the apparent position of an object against a background when viewed by
an observer from two different locations. These positions and the actual position of the object form a
triangle from which the apex angle (the parallax) and the distance of the object can be determined if
the length of the baseline between the observing positions is known and the angular direction of the
object from each position at the ends of the baseline has been measured. The traditional method in
astronomy of determining the distance to a celestial object is to measure its parallax.
Refers to a group of eyepieces that all require the same distance from the focal plane of the
telescope to be in focus. This means when you focus one parfocal eyepiece all the other parfocal
eyepieces, in a particular line of eyepieces, will be in focus.
The distance at which a star would show parallax of one second of arc. It is equal to 3.26 light-years,
206,265 astronomical units, or 30,800,000,000,000 km. (Apart from the Sun, no star lies within one
parsec of us.)
An object which cannot be resolved into an image because it to too far away or too small is
considered a point source. A planet is far away but it can be resolved as a disk. Most stars cannot
be resolved as disks, they are too far away.
A telescope in which the light is collected by means of a mirror.
The minimum detectable angle an optical system can detect. Because of diffraction, there is a limit
to the minimum angle, resolution. The larger the aperture, the better the resolution.
The angular distance of a celestial object measured in hours, minutes, and seconds along the
Celestial Equator eastward from the Vernal Equinox.
This is the angular speed at which the Earth is rotating. Telescope tracking motors drive the
telescope at this rate. The rate is 15 arc seconds per second or 15 degrees per hour.
36
TTerminator
UUniverse
VVariable Star
WWaning Moon
The boundary line between the light and dark portion of the moon or a planet.
The totality of astronomical things, events, relations and energies capable of being described
objectively.
A star whose brightness varies over time due to either inherent properties of the star or something
eclipsing or obscuring the brightness of the star.
The period of the moon's cycle between full and new, when its illuminated portion is decreasing.
Waxing Moon
Z-
The period of the moon's cycle between new and full, when its illuminated portion is increasing.
Zenith
The point on the Celestial Sphere directly above the observer.
Zodiac
The zodiac is the portion of the Celestial Sphere that lies within 8 degrees on either side of the
Ecliptic. The apparent paths of the Sun, the Moon, and the planets, with the exception of some
portions of the path of Pluto, lie within this band. Twelve divisions, or signs, each 30 degrees in
width, comprise the zodiac. These signs coincided with the zodiacal constellations about 2,000 years
ago. Because of the Precession of the Earth's axis, the Vernal Equinox has moved westward by
about 30 degrees since that time; the signs have moved with it and thus no longer coincide with the
constellations.
37
Appendix C - RS-232 Connection
Using the included NSOL software you can control your NexStar telescope with a computer via the RS-232 port
located on the computerized hand control and using the RS-232 cable (#93920). For information about using
NSOL to control your telescope, refer to the instruction sheet that came with the CD and the help files located on
the disk. In addition to NSOL, the telescope can be controlled using other popular astronomy software programs.
For detailed information about controlling NexStar via the RS-232 port, Communication protocols and the
RS-232 cable, refer to the NexStar SLT section of the Celestron web site at: http://www.celestron.com.
38
APPENDIX D – MAPS OF TIME ZONES
APC
OCEAN
C
(
Greenland
~
-a
·--=--
OR
(-;
t=:
ORTH
PAC F (
AT
NT
OC A
0
AN
-=
•
u
-10
H
oc
....
PAC FIC
AN
. a:....,
_...,._
-1:8&..000.000. 0'
_--
-CyllndtfcM, . , . _ ,
0
0
-
s...
1:00
-11
Hawaii
1000-
.......
3:00
4:00
$:00
-9
-8
-7
Alaska
6:00
-6
Pacific Mountain Central
Time Zones
39
7:00
8.:00
-5
-4
Eastern
....
..............
---
...t=:""-:a::'
11>.00
-3
-2
40
January - February Sky
N
I
•
•
•
••
••
•
•
•
•
•
•
•
•
•
•
•
fj
•
us
••
liirui~iopeia
•
Polaris
:;\
•
•
Triangulum
Ursa
Major
•
•
•
Virgo
•
r/ .- .
•
•
••
•
Aries
••
•
E. C l:
•
Hydra
Canis Minor
d
\.!)
Procyou
~rion
Betelgeuse
~
~
•
Canis~
•
I
s
•
•
•
•
•
•
•
March -April Sky
N
I
•
••
cassiopeia
•
•
~
"Cep~eus ~
•
•
·~
•
I
<:;
•
•
\.r
M.ll.ar.
•
s ~rr:f·§~ .
G:Jf/}
•
•
•
II
Castor
••
•
•
••
0
~r
()~ @)
•
•
•
• .::..·§55
•
~c::
•• •
•
t1r.f:.t£lnt~
&
•
Hydra/
•
•
d;
w
c5
Corvus
~
I;\
I
s
PrQ(.)I.QI1
May -June Sky
N
•
•
•
••
•
•
••
•
•
•
•
•
••
•
•
y,.e~c~'e":J ~oo'e":J
•
•
•
.D \
Ramfha<••
•
•
• •
•
•
•
•
...)COrona
a
\Bocealis Arctlm:,
--l\~~
•
• T
Serpens
(caput)
\
Ophiuchus
•
•
'\'
•
•
•
•
••
I
s
•
•
•
July _August Sky
N
I
••
••
•
•
•
•
•
•
f
I
Aries
•
._,/
Ursa
.
MaJor
Polaris
Triangulum
~ . ~assiop:i•)
••
Andromeda
.
~.···
y
•
••
~ms
•
~ :-.-
1kl:ld2.
Caron~
••
Yrg:a.
•oephinu;j
•
•
Serpens
•
•
Vephiuchus •
•• •
•
•
•
•
I
s
•
•
•
Borealis •
;.\(caput)
..
Cygn~ • •IfJ Hercules
• • • ""- LY:a .r • J
Rasolhague
G
C?('> .
Albireo
•
~isces~
~tes
•
••
••
.
•
•
•
•
•
September - October Sky
N
I
E--
.,.
•
Triangulum
~
•
;eo
~<1s
vs
I
s
•
•
• ••
• • -1.
•
•
<fv,;:q
•
~
Dephinus
•
•
¢.11tair •
r
November- December Sky
N
I
E--
•
•
••
•
•
•
••
-~
•
~
•
•
e,<o. •
•
••
iP~
~
•
••
tiari
•
•
•
•
•
••
Procyon
(3-0-0'<;,
0
~\
G
. o~
Triangulum
•
.
• • ·e'"='
~"
B etel.geu se
•
lliiil
•
•
•
•
•
•
•
~·
I
s
/
•
Celestron
2835 Columbia Street
Torrance, CA 90503
Tel. (310) 328-9560
Fax. (310) 212-5835
Web site at http://www.celestron.com
Copyright 2010 Celestron
All rights reserved.
(Products or instructions may change without notice or obligation.)
This device complies with Part 15 of the FCC Rule. Operation is subject to the following two
conditions: 1) This device may not cause harmful interference, and 2) This device must accept
any interference received, including interference that may cause undesired operations.
22087-INST
09-09
Printed in China
$10.00
NexStar 90 & 127SLT
Item #22097
Item #22087
Quick Set-up Guide
1
Your NexStar includes: optical tube; fork arm;
pre-assembled tripod; computerized hand
control; hand control holder; star diagonal;
two eyepieces; finderscope; accessory tray;
documentation including an owner’s
manual, The Sky® CD and NSOL Telescope
Control Software.
4
All three legs should be the same length to
provide a level platform for the telescope. A
bubble level is included (inset) to assist in leveling.
7
2
3
Assemble tripod by spreading the legs
out until the center leg brace is fully
extended.
5
Extend tripod legs 6 to 8 inches by
loosening the tripod leg locking knob
and pulling the leg to desired length and
re-tightening knob.
6
Place accessory tray on top of center leg
brace by lining up the grooves on the
tray to the post on the brace.
8
Once grooves are aligned, turn accessory
tray until it snaps into clips on each leg
brace.
9
Coupling screw
Hold the telescope fork arm and place
the bottom of the base inside the tripod
mounting platform as shown.
Thread the coupling screw into
the hole at the bottom of the fork arm
base. Tighten screw to secure the
fork arm.
Slide the optical tube dovetail into the fork
arm as shown above.
Quick Set-up Guide [cont]
10
Secure optical tube to fork arm by
tightening the screw located on the
inside of the fork arm assembly.
13
Insert the chrome barrel of the star
diagonal into the focuser and tighten the
two silver screws to secure
in place.
16
Slide Computerized Hand Control into
the hand control holder as shown above.
19
While observing, tube should be
positioned as shown above.
11
To attach the finderscope, loosen the silver
screw and slide finderscope into mounting
platform .
14
Select the low power (25mm) eyepiece
and insert it as shown above. Tighten
silver screw to secure.
17
Plug Computerized Hand Control into
the “Hand Control” port on the fork arm.
20
Before you can use your telescope, you
must insert 8 AA batteries.
12
Secure finderscope to mounting platform by
tightening the silver screw. The glass window of
the finderscope should be facing towards the
front of the telescope.
15
Attach plastic hand control holder to the
tripod leg.
18
Before you begin viewing, please
remember to remove tube lens cap.
21
Place AA batteries inside the battery
compartment located at the base of the
fork arm.
Before you can begin observing, you must setup your hand
control, align your finderscope and align your telescope. Step
by step instructions are included in the following Hand Control
Setup section.
Hand Control Guide
Before you can begin using your NexStar SLT, you must setup your computerized hand control and go through the
SkyAlign alignment procedure. In order for the NexStar to accurately point to the objects in the sky, it must first be
aligned with known positions (stars) in the sky. With this information, the telescope can create a model of the sky,
which it uses to locate any object in its database
1
Turn power switch (located on the side of
the fork arm) to “on”position. The light will
come on and the hand control will
display “NexStar SLT”.
4
Use the hand control direction arrow
buttons to point telescope at a distant
land object, like a telephone pole or at
night you can use the moon. Center and
focus the object in the 25mm eyepiece
of the telescope.
7
Once you have aligned your finderscope,
make sure to turn off the LED light to
conserve the battery. Now you are ready
to align the telescope. This will have to
be done at night.
10
The hand control will display the last
entered time and site information. Since
this is your first time using the NexStar,
press UNDO to enter your site and time
information.
2
You will notice that there are directional
arrows in the center of the hand control.
These only move the telescope. They
cannot be used to scroll through
menu features.
5
In order to accurately center an object
in the eyepiece it may be necessary to
change the slew speed of the motors.
To change the slew speed, press the
RATE button then select a number from
1 (slowest) to 9 (fastest).
8
When the display reads NexStar SLT,
press ENTER to begin the alignment
procedure.
11
Press ENTER to select City Database. Use
the Up and Down scroll buttons (located
on #6 and #9) and choose the closest city
to your present location. Press ENTER
after selecting the country, state and city.
3
Now you will need to align the finderscope.
Turn on the red LED light by turning the
knob shown above. When used for the first
time, remove the clear plastic disk that is
located between the battery clip and the
battery. See inset.
6
With the object centered in the eyepiece,
use the azimuth (right/left) and altitude
(up/down) adjustment knobs on the
finderscope to place the red alignment
dot directly over the centered object.
9
Use the UP and DOWN scroll buttons
(located on #6 and #9) to select
“SkyAlign” then press ENTER. Now you
will need to enter your site/time
information.
12
Using the numeric key pad enter your
time information. Press ENTER to
continue. Press UNDO to backspace.
Hand Control Guide [cont]
13
14
Now, using the Up and Down scroll
buttons (located on #6 and #9), verify the
time zone you are in and press ENTER.
16
15
Using the numeric key pad enter the
date. Press ENTER to continue. Press
UNDO to backspace.
17
If the finderscope has been properly
aligned, the alignment star should now
be visible in the field of view of the
eyepiece.
18
The hand control will prompt you to
center the bright alignment star in the
center of the eyepiece. Once centered,
press ALIGN. This will accept the star as
your first alignment position.
20
19
Use the directional arrow keys on the hand
control to slew (move) the telescope
towards any bright celestial object in the
sky. Center the object in the finderscope
and press ENTER.
For the second alignment object, choose
a bright star or planet as far from the first
alignment object as possible. Once again
use the directional arrow buttons to
center the object in the finderscope and
press ENTER. Once object is centered in
the eyepiece, press ALIGN.
21
TOUR
Repeat the process for the third
alignment star. When the telescope has
been aligned to the final star, the display
will read “Match Confirmed”. Press UNDO
to display the names of the three bright
objects you aligned to, or press ENTER to
accept these three objects for alignment.
Now that your telescope is properly
aligned, you are ready to find your first
object. Press the TOUR button on the
hand control. The hand control will
display a list of objects that are visible for
the date and location entered.
INFO
Press INFO to read information about the
object displayed. Press the DOWN scroll
key to display the next object. Press
ENTER to slew (move) to the displayed
object.
For general usage information, please consult your user’s manual.
If you have questions or problems with set-up, please contact
Celestron Technical Support: 310.803.5955
TheSkyX
First Light Edition
User Guide
Copyright 2010
Software Bisque, Inc.
Revision 1.0.4
2
Disclaimer
Information in this document is subject to change
without notice and does not represent a commitment
on the part of Software Bisque. The software
and/or databases described in this document are
furnished under a license agreement or
nondisclosure agreement. They may be used or
copied only in accordance with the terms of the
agreement (www.bisque.com/eula). It is against the
law to copy the software on any medium except as
specifically allowed in the license or nondisclosure
agreement. The purchaser may make one copy of
the software for backup purposes. No part of this
manual and/or databases may be reproduced or
transmitted in any form or by any means, electronic
or mechanical, including (but not limited to)
photocopying, recording, or information storage and
retrieval systems, for any purpose other than the
purchaser's personal use, without the express
written permission of Software Bisque.
Sky Charts created with TheSkyX First Light
Edition are for personal use only. They may not be
published in any form without express written
permission of Software Bisque, Inc.
TheSkyX includes routines from Astronomical
Algorithms Software, © 1991 by Jeffrey Sax, and
option to the book Astronomical Algorithms by
Jean Meeus © 1991 by Willmann-Bell. ISBN 0943376-35-2.
Non-exclusive use has been
specifically granted, in writing, by Willmann-Bell,
for use in TheSky. Serial Number U11A445.
Photographs in the AAO folder of TheSky’s media
are copyright Anglo-Australian Observatory (AAT
images) and/or ROE/AATB (UK Schmidt
Telescope images) and are reproduced with
permission. Photographs from the Anglo Australian
Observatory telescopes are by David Malin.
The photograph of the Milky Way is licensed from
Digital Sky LLC.
TheSkyX copyright 2010 Software Bisque, Inc. All
rights reserved.
TheSkyX First Light Edition is a trademark of
Software Bisque, Inc.
Winter Star Party panorama photographs courtesy
Art Mullis.
Mac and the Mac logo are trademarks of Apple
Computer, Inc., registered in the U.S. and other
countries.
All other product names are trademarks of their
respective owners and are used solely for
identification.
Written by Andre Bormanis
Revised: March, 2010
4
Table of Contents
Welcome to TheSkyX First Light Edition! .............. 7
Getting Started ............................................................................ 8
Updating Your Computer’s Video Driver ............................ 9
Installing TheSkyX First Light Edition.............................. 11
Removing TheSkyX First Light Edition ............................ 13
Having a Look Around TheSkyX ............................................. 14
Entering Your Location...................................................... 14
Tours ......................................................................................... 15
Photos from the Deep Sky ........................................................ 16
Viewing Astronomical Photos ........................................... 16
Your Sky Tonight ..................................................................... 17
What’s Up, Doc? ...................................................................... 17
The Calendar ............................................................................. 18
Exploring the Sky Chart ........................................................... 19
Changing the Date and Time.............................................. 19
Direction – The Look Commands ...................................... 20
Field of View...................................................................... 21
Setting the Field of View ................................................... 22
Stellar Cartography ................................................................... 23
Cosmic Coordinates .................................................................. 24
Stars and Constellations ............................................................ 26
Star Names ......................................................................... 26
Bright Stars and Dim Stars ................................................. 27
Setting the Magnitude Limit .............................................. 28
Other Chart Elements ......................................................... 29
A Star to Guide You: Polaris.............................................. 29
Double Stars ....................................................................... 30
Finding Mizar ..................................................................... 31
Variable Stars ..................................................................... 31
Classifying Stars: The Stellar Zoo ............................................ 32
Giants and Dwarfs .............................................................. 33
More About Constellations… ............................................ 34
Asterisms ............................................................................ 36
Some Tips on Using Star Charts ........................................ 36
An Interstellar Perspective ........................................................ 38
Closer to Home: Atmospheric Phenomena ........................ 39
Our Celestial Backyard: The Solar System .............................. 42
The Moon ........................................................................... 43
The “Classical” Planets ...................................................... 45
But Wait – There’s More .......................................................... 54
Beyond the Backyard: Our Home Galaxy ................................ 58
Beyond Our Galaxy: The Great Big Universe Out There ........ 59
What’s Up? – A Closer Look ................................................... 61
What’s Up? Setup............................................................... 62
Index .......................................................................... 63
6
Welcome to TheSkyX First Light Edition!
Most of you have never seen the sky. Not really. If
you live in a city or suburb, a pale blue or grey
dome looms overhead while the Sun is up, and a
darkish brown curtain hangs down at night, with
maybe a few sparks of light poking through here
and there if the clouds haven’t gathered and the
glare from buildings and cars and billboards isn’t
overwhelming.
The Sun and the Moon are
unmistakable of course, but the spattering of stars
you glimpse are probably strangers to you. Some of
them might even be planets – for most people, it’s
hard to tell the difference.
All of this is about to change. You have in your
hands an extraordinary tool for revealing not just
new worlds, but the entire universe. The night sky
is an incredible wonderland of diverse and
spectacular objects and phenomena. Some of these
breathtaking sights are created by tiny particles that
ply the fringes of our atmosphere. Others are
immense, ancient structures, incomprehensibly far
away.
TheSkyX First Light Edition will bring all of these
amazing marvels and more to your desktop. It will
help you learn the fundamentals of astronomy, the
most ancient science, and teach you how to
recognize just about everything in the real sky.
Whether you’re looking up from the streets of a
light-polluted city, or taking in the view from a
remote, pitch-black mountaintop, TheSkyX First
Light Edition will help you understand what you see
and find what you’re looking for.
You’ll also enjoy experiences that are only possible
through the magic of simulation and virtual-reality
programming. Faster-than-light flights through the
solar system, out-of-this-world views of the Earth
and Moon, and the orbital tracks of hundreds of
satellites are just some of the animations built into
TheSkyX First Light Edition. Trips through space
and time that were once possible only in the
imagination will be vividly brought to life on your
computer screen.
TheSkyX First Light Edition has something to offer
everyone, from the absolute beginner to the most
knowledgeable amateur astronomer. This User’s
Guide will help you navigate the basic features and
tools our unique program has to offer.
The sky is waiting for you. Let’s get started!
Getting Started
TheSkyX First Light Edition (hereafter referred to
simply as TheSkyX) is available for either Mac or
Windows operating systems.
Macintosh
TheSkyX for Mac can run on any Macintosh desktop
or laptop computer running OS X 10.5 (Leopard) or
later with a 1.25 GHz or faster G4 PowerPC
processor, or a 2 GHz or faster Core Duo processor.
You also need at least 512 MB RAM, 64 MB video
RAM, and 450 MB of disk space, a mouse or other
pointing device and a CD ROM drive.
8
TheSkyX First Light Edition User Guide
Windows
TheSkyX for Windows can run on any desktop or
laptop computer running Windows Vista or XP with
a 1.5 GHz or faster Intel Pentium 4, Pentium M,
Pentium D, or AMD K-8 (Athlon) or better
processor. You also need at least 512 MB RAM, 64
MB video RAM, and 450 MB of disk space, a
mouse or other pointing device and a CD ROM
drive.
Updating Your Computer’s Video Driver
Before installing and using TheSkyX, we strongly
recommend updating your computer’s video display
driver.
Our latest applications use OpenGL to display
accelerated graphics for smooth 2D and 3D
animation and high-frame rates. For the best
experience, make sure that your computer has the
latest version of OpenGL installed.
Installing Mac Video Drivers
The latest version of OpenGL is included with the
OS X software updates. Click the Apple icon, then
click the Software Update command to make sure
your Mac is up to date. That’s it.
Windows 7, Windows Vista and Window XP
Video Drivers
For all 32- and 64-bit editions of Windows, the
latest version of OpenGL is distributed as part of
your computer’s video driver (the video driver is
software that communicates with the video display
hardware).
9
In order to obtain the latest version of OpenGL, you
must install the latest video driver directly from the
original equipment manufacturer (OEM) of your
computer's video display adaptor.
Video driver software is updated very frequently, so
chances are you don't have the latest driver installed
on your computer right now.
To Properly Update the Windows Video Driver
and OpenGL
First, determine the make and model of your
computer’s video display adaptor. Both are listed in
the Windows Device Manager (see Windows Help
for details about accessing the Device Manager
from XP, Vista and Windows 7. Do not use
Windows Update feature to obtain latest video
drivers and do not use the video driver that is
supplied by Microsoft Windows as it does not
include the latest version of OpenGL or the latest
video driver for your video hardware.
Next, visit the Downloads page of the video driver
manufacturer: AMD (ATI), Intel, NVIDIA or S3
Graphics. From there, download and install the
latest video driver according to the video display
hardware manufacturer’s instructions.
After installing the latest Windows video driver,
you’re ready to install and run TheSkyX.
10
TheSkyX First Light Edition User Guide
Installing TheSkyX First Light Edition
Macintosh
Like all Macintosh software, TheSkyX is easy to
install. Insert the CD-ROM in the CD-ROM drive.
TheSkyX icon should appear on your screen.
Double click it. TheSkyX install icon should now
appear. Double click that icon and follow the
prompts. You’ll be asked for the all the usual stuff.
To launch TheSkyX, click Go > Applications from
Finder, then double-click on TheSkyX First Light
Edition icon.
Windows 7 and Windows Vista
To install TheSkyX under Windows 7 or Windows
Vista:
1. Log on as an administrator.
TheSkyX
requires administrative privileges to be
installed under Vista.
2. Insert the CD-ROM in the CD-ROM or
DVD drive.
3. Click Start > Computer.
4. On the Computer window, select the
removable storage device that holds
TheSkyX media, and then click the
AutoPlay button (it’s located in the tool bar
near the top of this window.)
5. On the AutoPlay window, click Run
Readme.htm.
6. After carefully reading the instructions in
the ReadMe file, click the Click Here to
Begin Installation link. Follow the onscreen instructions to complete the
installation.
11
Windows XP
To install TheSkyX under Windows XP:
1. Log on as an administrator.
TheSkyX
requires administrative privileges to be
installed under XP.
2. Insert the CD-ROM in the CD-ROM or
DVD drive and wait for the ReadMe file to
appear in a browser window. If XP’s
AutoRun is not active, then click Start >
My Computer, right-click on the removable
storage device that holds TheSkyX media
and then click Open. Next, double-click the
file named ReadMe.htm on TheSkyX media
to proceed.
3. After carefully reading the instructions in
the ReadMe file, click the Click Here to
Begin Installation link. Follow the onscreen instructions to complete the
installation.
To start TheSkyX, click Start > All Programs >
Software Bisque > TheSkyX First Light Edition >
TheSkyX First Light Edition.
We’ll discuss customizing TheSkyX for your
geographic location in a moment…
About This User’s Guide
Not every function and feature of the TheSkyX is
covered in this User’s Guide. The purpose of the
Guide is to familiarize you with the basic
organization and structure of our program, and to
introduce those of you who are new to the subject of
astronomy to some of its most important terms and
12
TheSkyX First Light Edition User Guide
concepts. We also hope the Guide will stimulate
you to become more interested in astronomy and
space science, and excited to start learning about the
extraordinary universe we live in.
More comprehensive information about TheSkyX
can be found on our website:
http://www.bisque.com
Removing TheSkyX First Light Edition
If you must remove or uninstall TheSkyX from your
computer please follow the procedure outlined
below.
Macintosh
1. From Finder, click Go > Applications to
open the Applications folder.
2. Drop TheSkyX First Light Edition
application to the trash. Note that you must
empty the trash before re-installing.
Windows
1. Log on as an administrator.
2. Click Start > Control Panel > Uninstall a
Program (or double-click the Add/Remove
Programs from XP).
3. Select TheSkyX First Light Edition from
the list of installed programs, and click the
Uninstall button (or click the Remove
button under XP).
***
13
Having a Look Around TheSkyX
The star chart display is the heart and soul of
TheSkyX. We call it the Sky Chart, to distinguish it
from the real thing. To the left of the Sky Chart
you’ll find the Command Center window with
vertical tabs to access the most commonly used
commands and options.
When TheSkyX is first launched, it attempts to
automatically set your location and the date and
time are read from your computer’s clock. You’ll
also notice that if you are using TheSkyX during
daytime, the sky it displays is blue. In a moment
we’ll describe how to change that to a night view
even during the day. Right now, let’s make sure
that the program is set to display the Sky Chart from
your location.
Entering Your Location
Home is where you hang your hat, and also where
most of you probably watch the sky. You can enter
your latitude and longitude, if you happen to know
it, or choose the name of the city you live in, or the
one closest to you, from the list in the Location
dialog box:
1. Highlight the Input item in the Main Menu.
2. Select the first item, Location.
A dialog box appears displaying options for setting
your location. From the List of Locations tab, if
you live in the U.S., double-click on United States.
A list of the major cities within your country will
then appear. You can choose your city, or the one
closest to where you live, by double-clicking on it.
Alternatively, you can enter your latitude and
14
TheSkyX First Light Edition User Guide
longitude or U.S. zip code from the Custom tab, or
double-click your site on the Earth Map tab. When
you’ve finished setting your location, close the
dialog box.
To save this setting, click the Save command from
the File menu.
***
Tours
Before we investigate the various menu and
“button” commands arranged across the top of the
screen, let’s explore some of the tours that have
been created to help you appreciate several of the
most common yet fascinating things you can see in
the sky.
Notice the series of tabs running vertically on the
right side of the Command Center window. Select
the tab labeled Tours. A list of available tours is
displayed:
•
•
•
•
•
•
•
•
•
•
•
Analemma
Angular size of Mars
Coordinates - Equatorial
Coordinates - Horizon
Mercury evening visibility
Mercury morning visibility
Moon cycle - size and phase
Motion of Barnard’s Star
24-Hour Motion of Saturn’s Moons
Rotation and Phase of Mercury 2008
Rotation and Phase of Venus 2008
15
•
•
•
•
Saturn from Earth Over 10 Years
Venus and Mercury Paths
What Was That? (Iridium Flare Example)
Winter Constellations
Go ahead and take one of the tours. Highlight one
that sounds interesting, then click the Start button.
Or, click the Run All button to watch them
consecutively.
***
Photos from the Deep Sky
For more than a century astronomers have been
taking pictures of the sky. In recent years, digital
imaging sensors have replaced film to capture even
more remarkable views of the moon and planets, as
well as star clusters, nebulas, and galaxies.
Relatively modest amateur telescopes, equipped
with digital cameras, can capture images that rival
the best photographs taken by professional
observatories just a couple of decades ago.
TheSkyX has a veritable art gallery’s worth of
fantastic space images you can look at anytime.
Browsing these images will give you a taste of the
extraordinarily diverse number of objects that
populate the night sky.
Viewing Astronomical Photos
At the bottom of the list of vertical tabs on the
Command Center, you’ll see a tab called Photos.
Select it.
16
TheSkyX First Light Edition User Guide
As you scroll through the list of objects, a small
picture of each will be displayed below the list.
Click the Show in Photo Viewer option to view
them in a separate window.
***
Your Sky Tonight
This section of the User’s Guide is intended to help
you explore the night sky from your location on any
date, at any time. You’ll be able to answer the
question: “When I head outside tonight at say, 9
p.m., what am I going to be able to see?” You’ll
also learn how to plan ahead for special events, like
meteor showers and lunar eclipses.
For a given location, what you can see in the sky on
any given night depends on the date and time. The
stars that are visible at 9 p.m. on a December night
are very different from the ones you would see at 9
p.m. in June, for example. And the Moon and
planets follow their own unique celestial paths –
their positions, and their brightness, vary from
month to month and year to year.
***
What’s Up, Doc?
TheSkyX includes a menu command that will
display a select list of objects that will be visible in
your night sky on the current date. You can set the
parameters of this list to choose the kinds of objects
you’re most interested in seeing.
17
Go to the Tools menu. The first item in the Tools
menu is What’s Up? Select it.
A list of objects that will be visible from your
location in tonight’s sky will be generated. When
you highlight an item and click the adjacent
Information button, various astronomical data
regarding that object will be displayed.
Some of these objects, and the data displayed with
them, may be unfamiliar to you.
We’ll be
describing most of the information in the What’s
Up? command in more detail on page 61.
***
The Calendar
Mankind has been using calendars of one kind or
another to mark the passage of time for thousands
of years. The Calendar feature of our program
charts the phases of the Moon, sunrise and sunset;
you can even display and print a calendar for a
single month or the entire year.
If you select the Date & Time tab on the Command
Center window, a small calendar for the current
month will be displayed. Here’s a great (if we do
say so ourselves) feature: if you click on any date in
the calendar, the Sky Chart automatically shifts to
show you what the sky will look like on that date,
for the current time. Notice also that the four major
phases of the Moon are displayed in the calendar.
18
TheSkyX First Light Edition User Guide
For a more detailed calendar, go to the Tools item
in the Main Menu. Scroll down to Calendar and
select it. A larger, printable calendar is displayed.
Note that you can select various kinds of
information to be included in the calendar by
checking the appropriate boxes on the right-hand
side of the window.
***
Exploring the Sky Chart
In this section of the User’s Guide we’ll focus on
how to adjust and navigate the Sky Chart. The best
way to learn our program is simply to use it. Feel
free to play around with the various buttons and
menu commands you see in the tool bars. TheSkyX
won’t break, and it won’t bite you.
Changing the Date and Time
The clock built into your computer is constantly
tracking the date and time. TheSkyX reads this and
displays whatever is above your horizon right now,
but it can also show you the sky for different times
of day or night.
Select the Date & Time tab from the list of vertical
tabs on the Command Center window. Below the
calendar there is an item called Set Specific Time.
Click it.
You’ll see a list of different “times” – not in hour
and minute format, but in terms of astronomical
events, for example, sunset, moonrise, evening
(end twilight), and so on. When you select one of
these options, the Sky Chart shows you what the
19
sky will look at that time for the current date. Try
several of the options and watch how the chart
changes.
You can make time speed up and even go
backwards. In the Tools menu, choose the item
called Time Skip. Try one of the various options.
The Sky Chart will continue moving backward or
forward in time until you select Stop, or the Use
Computer’s Clock option.
Finally, you can also enter a specific date and time
by selecting the Input item from the Main Menu
and choosing Date & Time (note there is also a
shortcut key for this displayed within the menu –
TheSkyX will always display shortcut keys in the
menu whenever they are available).
***
Direction – The Look Commands
Our eyes can only see a small portion of the sky at a
time. TheSkyX can show you the entire sky at once,
but it’s often more useful to focus the display on
one part of the sky at a time, to match what you can
see in the real night sky with your unaided eyes.
Changing the direction of your view is
accomplished with the Look commands. These can
be found in the Orientation menu, but they are also
available to you as buttons in the Orientation tool
bar.
By default, the Sky Chart is displayed looking
south. Click the East button in the Orientation tool
bar. Note that the star field has changed; the
20
TheSkyX First Light Edition User Guide
compass direction displayed at the bottom of the
screen indicates E, for east. Experiment with the
other compass direction buttons.
In addition to the compass direction buttons, a set of
arrow buttons can be used to shift your viewing
direction incrementally. Click the right arrow
button. Notice how the view shifts slightly to the
left (how far the Sky Chart shifts depends on your
field of view, discussed below), just as if you were
outside, looking at the real sky, and turning your
head to the right. The left, right, up and down
buttons function similarly (if your computer’s
monitor is small, or the screen resolution is low, the
entire toolbar may not fit on the screen, so you may
need to click the “>>” symbol to display the up and
down buttons), mimicking the movement of your
head in the indicated directions.
You can also press and hold the CONTROL key then
drag the mouse to adjust the position of the Sky
Chart.
***
Field of View
You probably know that a circle can be divided into
360 degrees. Imagine a pie cut into six equal slices.
The angle between the edges of a given slice is 360
/ 6 = 60 degrees. Astronomers measure angles in
degrees, and fractions of a degree: each degree is
divided into sixty minutes, and each minute is
divided into sixty seconds.
When you look at the sky, you can only see a
portion of it. Imagine for a moment that the sky is
21
an immense spherical bowl above your head. When
you look up at it, you’re seeing a slice of the sky
that spans a particular angle.
Assuming you have normal peripheral vision, that
angle is about sixty degrees – one slice of our
imaginary pie. Another way of saying this is your
field of view is sixty degrees. Some people can see
a little more, and some a little less, but sixty degrees
is about average for adults.
When you look at the sky with binoculars or a
telescope, what you see is magnified – in effect, you
bring the sky closer, making it easier to see detail
and faint objects. The downside of magnification is
that it always reduces your field of view, sometimes
to just a fraction of a degree. Generally speaking,
the greater the magnification, the smaller the field
of view.
TheSkyX allows you to set the field of view to any
angle, from 235 degrees to a fraction of a degree.
This is very useful when you’re trying to understand
how much of a particular constellation or star field
might be visible in a pair of binoculars or a small
telescope.
Setting the Field of View
The simplest way to change the field of view is to
use the Zoom In and Zoom Out buttons. The
current field of view is displayed next to these
buttons. Click that button. A list of preset fields of
view is displayed. Some of these correspond to the
field of view of a typical pair of binoculars or
amateur telescope.
22
TheSkyX First Light Edition User Guide
The Wide Field option shows you the sky from
horizon to horizon, 180 degrees. The Naked Eye
option gives you a 100-degree field of view – a bit
wider field than what you can actually see with your
eyes, but we wouldn’t want you to miss anything.
You can also define a zoom box to zoom in on a
particular area of the Sky Chart. Place your cursor
on one corner of the area you want to zoom in on.
Click and hold while you move your cursor to the
opposite corner, then click anywhere inside the
zoom box to enlarge it (you can click outside the
zoom box to cancel this operation).
***
Stellar Cartography
Just as you would use a map to find your way
around a city, state, or country, celestial maps or
star charts are designed to help you find your way
around the sky.
Use your mouse or track pad to move the arrow
around the Sky Chart. You’ll notice that when the
tip of the arrow touches an object, an information
box describing that object is automatically
displayed. The kind of information displayed
depends in part on the nature of the object, but one
thing that is always displayed is the location of the
object. This is indicated by two different sets of
coordinates.
23
Cosmic Coordinates
Maps of the Earth identify the location of landmarks
with two numbers: latitude and longitude. Latitude
is measured in degrees north or south of the equator,
and longitude is measured in degrees east or west of
the Prime Meridian.
A similar system is used for objects in the sky. The
celestial equator divides the sky into two
hemispheres, north and south.
The celestial
equivalent of longitude is called right ascension
(TheSkyX uses the abbreviation RA) and the
equivalent of latitude is called declination (dec).
Right ascension is measured in hours, minutes, and
seconds, from 0 to 24. This may seem odd at first,
but there’s a very good reason for this peculiar
convention: the Earth is rotating. It turns around
once on its axis in 24 hours, but from our terrestrial
perspective, it looks like the sky is rotating around
the Earth every 24 hours. Right ascension is
measured eastward from the constellation Aries, the
Ram. Specifically, 0 hours RA, the First Point of
Aries, is the position in the sky where the Sun
crosses the celestial equator on the first day of
spring.
Declination is measured in degrees north or south of
the celestial equator. The celestial equator is 0
degrees declination. The north celestial pole is
located at 90 degrees declination (Polaris, the North
Star, has a declination very close to 90 degrees).
The south celestial pole is at minus 90 degrees
declination. You can also translate right ascension
into degrees: a complete circle has 360 degrees;
24
TheSkyX First Light Edition User Guide
dividing 360 by 24 gives 15, so every hour of right
ascension is equal to 15 degrees.
Imagine a line running across the sky from due
north to due south, splitting the sky in two. This
line is called the meridian. When a celestial object
crosses the meridian, it is also at its highest altitude
in the sky. This is called the transit time. Generally
speaking, the best time to observe a celestial object
with a telescope is when it’s crossing the meridian.
This brings us to another way of identifying the
location of an object in the sky: altitude and
azimuth. Altitude is simply the number of degrees
the object is above the horizon, from 0 (on the
horizon) to 90 (directly overhead). Be careful not to
confuse altitude with declination – they are not the
same thing.
Azimuth indicates the compass direction of an
object. Specifically, it is the number of degrees east
of north that you need to turn to see the object. Due
east, for example, is 90 degrees azimuth.
The problem with using altitude and azimuth for
astronomical objects of course is that these numbers
are constantly changing as the Earth rotates.
TheSkyX, however, can calculate these numbers
instantaneously, making it easier to know what
direction to look when you’re outside in the dark,
trying to find a particular object at a specific time.
***
25
Stars and Constellations
There are some 6,000 stars visible to the naked eye.
Most of these stars can only be seen from locations
far from the bright lights of a city or town. If you
really want to see the stars, you either have to go to
Hollywood or get out of Dodge.
Star Names
Some of the brighter stars have proper names, but
most don’t – there are just too many to give each
one a name. Instead, astronomers have devised a
system that assigns names to stars based on their
brightness and the name of the constellation they
belong to. Following a centuries-long tradition, the
brightest star in a constellation is designated by the
first letter of the Greek alphabet, Alpha, followed
by the genitive form of the name of its constellation.
For example, the brightest star in the constellation
Orion is called Alpha Orionis. It also has a proper
name: Rigel. (We’ll talk more about constellations
later. Right now we’re going to focus on individual
stars.) When the letters run out, stars are identified
by various alphanumeric designations.
A funny thing about Rigel: even though it’s the
brightest star in Orion, its designation is Beta
Orionis.
Astronomers originally thought that
Betelgeuse, another star in Orion, was a little bit
brighter, but improvements in photometers in the
20th century revealed that Rigel is actually the
brighter star (it’s possible that Betelgeuse might
have been brighter in the past, when astronomers
first began to designate stars with Greek letters).
26
TheSkyX First Light Edition User Guide
Bright Stars and Dim Stars
Long before the invention of the telescope,
astronomers also came up with a numerical system
for classifying stars by their brightness. They
decided that the brightest stars would be called First
Magnitude. Those half as bright as First would be
called Second Magnitude, then Third Magnitude,
and so on down to Sixth Magnitude, which denotes
the dimmest stars visible to the naked eye.
We use a modified form of this system today. The
brightest star in the nighttime sky is called Sirius.
It’s in the constellation Canis Major, the Big Dog,
and it’s sometimes called the Dog Star. Its
magnitude is minus 1.4, which we write as -1.4.
This may seem a little confusing, but it isn’t that
hard to understand. A couple of centuries ago,
astronomers decided to make the magnitude scale
more precise. They knew the Sun and Moon and
some of the planets are brighter than the brightest
stars, so these were given negative magnitudes.
They also realized that a First Magnitude star is
actually a bit more than twice as bright as a Second.
In order to keep Sixth Magnitude as the faintest star
visible to the naked eye, astronomers recalibrated
the magnitude system to follow a logarithmic scale.
Each stellar magnitude is about 2.5 times brighter
than the next lower magnitude.
With a telescope, you can see stars much dimmer
than Sixth Magnitude. TheSkyX database includes
stars down to about 12th Magnitude.
On a clear, moonless night, people who live in cities
or suburbs can rarely see stars dimmer than Third
Magnitude. If you’re just starting to learn the
27
names of the brighter stars and constellations, you
should set the magnitude filter in TheSkyX to
Second or Third magnitude. That way, when you
go out at night to compare what you see on your
computer to what you can see in the real sky, you
won’t be confused by a screen display that shows
more stars than you can actually see from your
location.
Setting the Magnitude Limit
This command tells TheSkyX to only display stars
brighter than a selected magnitude.
1. Choose the Chart Elements tab from the
Display menu, or click this tab on the Command
Center Window.
2. Highlight the Celestial Objects text by clicking
on it.
3. Click the Show Attributes button.
4. Near the middle of the Chart Elements tab
you’ll see a button labeled Magnitude Limits.
You can enter a value between 30.0 and -6.0, or
change the magnitude using the slider.
Note: you may need to stretch the Chart
Elements window to access the slider. You can
adjust the size of a dialog box by moving the cursor
to the edge of the box, then clicking and dragging it
to the desired size. You can also move the box
anywhere on the screen.
Notice as you move the slider how the number of
stars on the Sky Chart changes to reflect the
changing magnitude limit.
28
TheSkyX First Light Edition User Guide
Other Chart Elements
Like land maps, star charts can be overlaid with a
variety of lines and markings intended to highlight
specific celestial features and help you find objects
at specific coordinates.
The Chart Elements menu lets you display or hide
various reference lines and symbols, but you should
be aware that even though the cosmos mostly
consists of empty space, a star chart can get very
crowded very quickly. The celestial equator and
lines of right ascension and declination can be
added to the Sky Chart, for example. Experiment
with this feature by clicking on the box next to a
listed chart element to see how it affects the display.
***
A Star to Guide You: Polaris
For people living in the northern hemisphere,
probably the most noteworthy star is Polaris, the
North Star. It always stays in the same part of the
sky, every night, 365 days a year. The reason for
this is fairly simple: Polaris happens to be located
almost directly above our North Pole. As the Earth
rotates on its axis, other stars rise and set, but
because Polaris is right above the pole, it always
seems to stay in the same place.
How high Polaris is above your horizon is a direct
way to find your latitude. If Polaris is 40 degrees
above the local horizon, for example, you must be
somewhere on the 40th latitude line. Philadelphia
and Denver are both very close this latitude, as are
Naples, Italy and Beijing, China. The stars you can
see on any given date and (local) time are
29
essentially the same for all of these cities, and any
other place along this line of latitude.
More than anything else, latitude determines what
you can see in the sky. The North Star is not visible
from the Southern Hemisphere, as are most of the
stars and constellations near it. And there are all
sorts of stars and constellations visible from the
Southern Hemisphere that we never get to see in the
North (the Moon and planets are visible from both
hemispheres). TheSkyX can show you what the sky
would look like from any place in either
hemisphere.
***
Double Stars
A little more than half of all stars actually travel in
pairs, orbiting each other in space. The American
astronomer Henrietta Leavitt once quipped that
three stars out of every two are double. Most of
them appear as single stars to the naked eye. You
need good binoculars or a small telescope to resolve
them as double stars (there are also triple stars and
groups consisting of four or even more stars).
Some double stars are true binaries, meaning they
are gravitationally bound to each other and orbit a
common point in space. Others only appear to be
double because they happen to lie along the same
line of sight from Earth, but are in fact many light
years apart and not tied to each other by gravity.
One of the best-known double stars in the sky is
called Mizar. It’s located in the handle of the Big
Dipper.
30
TheSkyX First Light Edition User Guide
Finding Mizar
Mizar is only visible from the Northern
Hemisphere, and is easiest to find in the evening
sky in Spring.
Select the Find tab from the vertical tabs on the
Command Center window.
Type Mizar into the “Search For” box, then click
the Find Now button. A double red “bull’s eye”
will encircle the star in the Sky Chart.
The Big Dipper is one of the northern sky’s most
recognizable asterisms (this term is described
below). Being able to find it will help you find
other nearby constellations, such as Cassiopeia.
Once you’ve mastered these constellations, others
will be easier to learn.
Another good thing about being able to find the Big
Dipper: it will make it easy for you to find Polaris,
and therefore true north. The two stars at the end of
the cup of the dipper point to Polaris. Imagine a
line connecting these two stars. Extend it in the
direction the cup is pouring, about five times the
distance between the two stars. The star you see at
the end of that line is Polaris.
***
Variable Stars
Fortunately for us, and everything else that lives on
Earth, the Sun radiates energy at a very nearly
constant rate. But there are some stars that change
in brightness dramatically over the course of a few
months, and in some cases, just a few days or even
31
hours. These are called variable stars, and TheSkyX
distinguishes them with a small red “v” to the lower
left of the star.
The most notorious variable star is called Algol, a
name derived from an Arabic word that means
demon. Located in the constellation Perseus, its
rhythmic dips in magnitude can easily be observed
with the naked eye. Every 2.867 days, over the
course of just a few hours, Algol falls from second
magnitude (2.1) to third (3.4) and back. During
these periodic dimmings, you can gauge its
changing brightness by comparing it to other nearby
stars. The evening sky in Autumn is the easiest
time to find this fascinating object (it is only visible
from the Northern Hemisphere). It may have been
considered demonic in ancient times, but today we
know this innocent star has a companion that orbits
it every 2.867 days.
Algol dims when that
companion passes in front of it from our
perspective. Such stars make up a special class
called eclipsing binaries.
***
Classifying Stars: The Stellar Zoo
Stars differ not only in their brightness, but also in
their size, surface temperature, and chemical
composition. The one thing they have in common
is that they are all spherical – although some spin so
fast they tend to bulge in the middle!
All stars are basically immense balls of intensely
hot gas that generate heat and light through a
process called nuclear fusion. The temperature and
32
TheSkyX First Light Edition User Guide
density in the core of a star are so great that lighter
atoms smash into each with enough force to fuse
into heavier atoms. In our own Sun, for example,
atoms of hydrogen fuse to produce atoms of helium
(this process involves several intermediate steps).
The fusion process releases energy in the form of
electromagnetic radiation – light.
By spreading starlight into a spectrum, astronomers
can learn the temperature and chemical makeup of
stars. After studying thousands of stars, it became
clear that stars fall into various categories, or
classes. Some are massive and bright, and have
relatively short, tumultuous lives. Others are small
and dim, and can shine steadily for tens of billions
of years.
A letter and number system is used to define stars in
terms of their most important physical
characteristics, and these designations are displayed
when you point to a star in the Sky Chart. A more
complete discussion of spectral classes and the
physics of stars can be found in any introductory
astronomy text.
Giants and Dwarfs
When you see a bright star in the sky, there are two
possibilities: the star is close by and relatively
average in size, or it is far away and gigantic.
Rigel is the brightest star in the constellation Orion.
It is nearly 800 light years away, but is the seventh
brightest star in the sky. It is a whopper, with a
diameter of about 100 million kilometers. The Sun,
by comparison, is about 1.4 million kilometers
across.
33
Astronomers
distinguish
between
apparent
magnitude and absolute magnitude.
Apparent
magnitude is how bright a star looks in the sky.
Absolute magnitude refers to how bright a star
would appear if it were located exactly 10 parsecs
(32.6 light years) away. The apparent magnitude of
Rigel is about 0.2, but its absolute magnitude is
nearly -7.0.
***
More About Constellations…
The desire to find order in nature, even where none
exists, seems to be built into the human brain.
When you look up at the sky on a dark, clear night,
the sheer number of stars can be overwhelming.
Our distant ancestors must have been in awe of
those countless lights randomly scattered across the
sky like diamonds.
Because of our instinctive need to find order,
cultures all across the globe have organized stars
into distinctive patterns called constellations. These
patterns are purely a product of the human
imagination. Nature had nothing to do with
creating them.
The constellations we recognize today have mostly
come down to us from the ancient Greeks. Many of
them represent mythological figures. Orion, for
example, one of the most prominent constellations
visible in northern wintertime, represents a heroic
hunter who first appeared in one of the great epics
of classical Greek literature, The Odyssey. Orion is
accompanied by two hunting dogs that are also
34
TheSkyX First Light Edition User Guide
immortalized in constellations: Canis Major and
Canis Minor, the big and little dogs, respectively.
When you look at Orion, it isn’t hard to imagine the
figure of a hunter with a raised arm wielding a club.
You can see one classic representation of this figure
by going to the Display menu and selecting
Constellations & Asterisms Options. You can
display line drawings, mythical figures, and
constellation boundaries by checking the
appropriate boxes. You can also use the slider
labeled Transparency to adjust how bright these
renderings appear.
For many other constellations, the connection
between its array of stars and what it is supposed to
represent is difficult to see, to say the least. They’re
a little more like abstract art, intended to represent
the idea of a thing rather than the thing itself.
Drawing lines between the stars of a given
constellation provides a simple “stick figure” view
of that constellation. When astronomers think about
constellations at all, this is how they usually think
of them. The more fanciful mythological drawings
of constellations became popular in the early 17th
century, especially in the gorgeous star charts
engraved by the great German celestial cartographer
Johann Bayer (Bayer is also credited with creating
the system that designates stars with Greek letters
and the genitive name of their constellations, as
described previously).
When the constellations we recognize today were
originally created, a number of stars were left over –
that is, not all stars fit into the established patterns.
35
To avoid confusion, astronomers designated
boundary lines between the constellations. Not
unlike borders between countries, any star that falls
within the borders of a given constellation is said to
belong to it, whether it was included in the original
depiction of that constellation or not.
Asterisms
There are familiar patterns of stars that don’t quite
qualify as constellations. Astronomers call these
patterns asterisms. The Big Dipper and the Pleiades
(the Seven Sisters) are probably the two most
familiar examples. In Japan, the Pleiades are called
Subaru. You’ve probably seen them driving around
your neighborhood.
***
Some Tips on Using Star Charts
Learning how to connect what you see on a star
chart to what you see in the real sky takes some
time. We’re going to show you a step-by-step
process that will make it easier for you to find
common stars and constellations. With a little
patience and practice, you’ll soon become an
expert.
First of all, when you go outside and look at the
sky, you need to know what direction you’re facing.
In particular, you need to know how to find true
north. City streets often lie along north/south and
east/west lines, but this isn’t always the case. If you
aren’t sure which way is north at your viewing
location, use a magnetic compass to find it.
36
TheSkyX First Light Edition User Guide
When hundreds of stars are displayed on your chart,
finding individual stars and constellations can be
very challenging. But if you limit the number of
stars in the chart to just a few dozen of the brightest
stars, you’ll have a much easier time learning the
sky.
Printing a chart to take with you when you go
outside is also very helpful. TheSkyX can print any
chart it displays. You can print an “all sky” chart,
or select a particular part of the sky you’re
interested in learning.
Choose File from the Main Menu.
At the bottom of the menu, you’ll see two items:
Print and Print Setup (if you have more than one
printer connected to your computer, Print Setup can
be used to select the printer you’d like to use).
Select Print.
An “Export Chart” dialog box appears on the
screen. TheSkyX allows you to print to a file as well
as directly to a printer. The Sky Chart as currently
displayed on the screen will be printed. TheSkyX
prints stars in black, leaving the sky white (if you
have a color printer, stars brighter than 6th
magnitude are printed as yellow circles). The size
of the star is proportional to its magnitude. Nonstellar objects are printed using the symbols that
appear in the Display > Map Like Sky Charts.
You can choose the orientation of the printout and
other printing parameters by clicking the Page
Setup button. When you’re ready to print, simply
click the Print button in the “To Printer” box.
37
The best time to start learning the sky is a clear,
cloudless night, when there is no moon or at most a
crescent moon. Moonlight can interfere as much as
city lights when it comes to seeing the stars, and if
the moon is close to Full, you probably won’t be
able to find any but the very brightest stars and
planets. You also want to be in an open space, a
place where there are no tall buildings, trees, or
annoying artificial lights to interfere with your
viewing. Make sure in particular that you have a
clear view to the north.
When you get to your observing site, give your eyes
at least a few minutes to adapt to the darkness.
You’ll need a flashlight to read the chart of course,
but you should use one that has a red filter. These
can be bought at most stores that sell telescopes, or
you can simply tape a piece of transparent red film
over a standard flashlight. Using only red light will
help preserve your night vision. If you take your
computer outside with you, the Display > Show
Night Vision Mode command will help preserve it,
too.
***
An Interstellar Perspective
Our Sun is but one of billions of stars in the Milky
Way galaxy. For centuries, astronomers have been
charting the positions of other stars in our galaxy,
and have accurately determined the distances to
many thousands of them. This information allows
us to step outside our solar system, in effect, and see
what the Sun and other stars in our part of the
38
TheSkyX First Light Edition User Guide
galaxy would look like from dozens of light years
away.
TheSkyX includes a utility for showing this to you.
Choose Tools from the Main Menu. Near the
bottom of the pull down menu, you’ll see an item
called 3D Stars. Select it. A view of our Sun and
its neighbor stars from outside our solar system is
displayed. Using the slider near the bottom left of
the screen, you can move from up to 2000 light
years away from the Sun. The Filter Stars by
Distance from the Sun slider will increase or
decrease the number of stars in the display.
***
Closer to Home: Atmospheric Phenomena
As we mentioned earlier, some of the most
interesting things we can see in the sky are
happening right above our heads, in the upper
atmosphere.
Meteors and Fireballs
You’ve probably seen a so-called shooting star
(maybe you’ve even wished on one). A shooting
star isn’t really a star at all, but a grain of space
dust.
When one of these particles hits our
atmosphere, it’s traveling at tens of thousands of
kilometers an hour. Friction makes it glow white
hot, turning it into a meteor. It may seem surprising
that a speck of dust at the edge of space could create
a streak of light visible from the ground, but even
the brightest meteor is rarely bigger than a pea.
The flying dust grains that cause meteors mostly
come from the tails of comets. Several tons of this
39
material falls to Earth every single day. If you get
away from the lights of the city and watch the sky
on a moonless night for an hour or two, you’ll see at
least a few meteors – maybe quite a few. They’re
falling everywhere, all the time.
Once in a while something much larger than a speck
of dust falls to Earth and creates a spectacular
fireball. Fireballs can blaze across the sky with
such intensity that they literally light up the
landscape. They can range in size from a few
centimeters to several meters. Bits and pieces of
them sometimes survive the fiery descent through
our atmosphere and crash into the ground. These
fragments are called meteorites.
Meteorites are chunks of asteroids and they fall into
three main categories, based on chemical
composition.
Iron meteorites are the most
commonly found because they are very distinctive,
consisting of ninety percent iron with a bit of nickel
mixed in. They are extremely dense, and have
magnetic properties.
Stony meteorites look more like common rocks.
They are the most common form of meteorite but
aren’t found as often as iron meteorites for two
reasons: they look like ordinary, everyday Earth
rocks, and they can’t be located using a metal
detector.
The third class is the stony irons, which, as the
name suggests, are a mixture of the iron and stony
types.
40
TheSkyX First Light Edition User Guide
A few people around the world make a good living
hunting meteorites. A decent-sized specimen can
be worth thousands of dollars to a museum or a
private collector. A really big meteorite with an
unusual composition can be worth millions.
Something to think about next time you see a
fireball…
Meteor Showers
The dust trails left by comets that have visited the
inner solar system follow predictable orbits around
the Sun. Several times a year Earth passes near one
of these cosmic debris trains, resulting in a meteor
shower. Halley’s comet, which has a 76-year orbit,
is responsible for two annual meteor showers, the
Eta Aquarids in early May, and the Orionid shower
in mid-October.
Have you ever looked at a set of railroad tracks and
noticed, as they stretch into the distance, how they
seem to converge to a single point? A similar effect
can be seen during a meteor shower. The debris
“train” of the shower’s parent comet follows the
tracks of an imaginary railroad. If you pay attention
to the direction most of the meteors in a particular
shower seem to be coming from, they all converge
back to the same point in the sky – the “vanishing
point” of the tracks of the debris train. This is
called the radiant. TheSkyX plots the radiant for all
annual meteor showers and estimates the date and
time they are expected to peak.
To display meteor shower radiants, select the Chart
Elements tab from Display menu. Within the list of
elements, there is an item called Reference Objects.
41
Click it, and a new list of items is displayed. Check
the box next to Meteor Shower Radiants.
The radiants for all meteor showers will now be
displayed on the Sky Chart. If you move the cursor
to the center of any radiant, details on that shower,
including when it is expected to peak, will be
displayed.
The Northern (and Southern) Lights
The Northern Lights, or aurora borealis, can be as
stunning as any fireworks display. They appear as
curtains of colorful, shifting light, suspended high
up in the night sky. Unfortunately, they are
generally only visible from far northern latitudes,
and when they might occur is notoriously hard to
predict.
Auroral displays are caused by charged particles
from the solar wind striking the Earth’s upper
atmosphere. Our planet’s magnetic field guides
these particles toward the poles, which is why
auroras are only visible from high northern and
southern latitudes (the auroral light show is called
the aurora australis in the southern hemisphere).
***
Our Celestial Backyard: The Solar System
Our Sun is one of countless stars in the universe.
The planets that circle the Sun are its family,
figuratively speaking, and it would be hard to deny
that Earth is its favorite child. The planet we call
home is located at just the right distance to be
42
TheSkyX First Light Edition User Guide
neither too cold nor too hot for liquid water and life
to flourish on its surface. But the rest of the Sun’s
family – the solar system – is full of diverse and
fascinating characters. Some of them may once
have harbored some form of primitive life. These
bodies are much, much closer than even the next
nearest star, and so astronomers like to say they
inhabit our celestial backyard.
Finding a planet in TheSkyX is simple. Simply go
to the Edit menu and choose Find. Type the name
of the planet in the Search For box. Information
about the planet will be displayed. You can center
the planet in the Sky Chart by clicking the Center
button near the bottom of the screen. Note that this
same procedure applies to every object in
TheSkyX’s database. If you’re unsure of an object’s
name or catalog number, click the Advanced button
to view a comprehensive list of searchable objects.
The Moon
The most familiar object in the night sky is
undoubtedly the Moon. It’s been Earth’s constant
companion for more than four billion years.
Scientists believe that the Moon was formed shortly
after the birth of the solar system, when a molten
planet about the size of Mars smashed into the
Earth. That planet is no longer around, but much of
the fallout from its impact settled into orbit around
us and aggregated into the Moon.
The Moon is tidally locked to the Earth. Our
gravitational pull, over millions of years, slowly put
the brakes on the rotation of our satellite. Today the
Moon makes one complete rotation for every single
orbit it makes around the Earth. Because of this, the
43
same side of the Moon always faces the Earth. We
had no way of seeing the far side of the Moon until
spacecraft were sent there in the late 1950’s. Some
people mistakenly call the far side of the Moon the
dark side of the Moon. With all due respect to Pink
Floyd, the Moon has no “dark” side. Over the
course of a lunar day (about 29.5 Earth days) the far
side of the Moon gets just as much sunlight as the
side facing us.
As the Moon orbits the Earth, it goes through its
familiar phases, from New to Full and back again.
TheSkyX can tell you the phase the Moon on any
date, at any time. It is automatically displayed on
the star chart in its current phase and proper
location whenever it is above the horizon. The orbit
of the Moon is not a perfect circle, but an ellipse,
meaning it has an oval shape (in fact, all orbits,
from artificial satellites to planets to stars circling
the centers of galaxies, are ellipses). TheSkyX will
tell you the current distance between the Earth and
Moon.
The Moon is one of the most interesting things to
look at in binoculars or a telescope. Even a little
magnification will reveal the larger lunar craters,
and help you see the mare, the so-called lunar
“seas,” which are really cooled lava basins. The
Moon has no atmosphere, so liquid water cannot
exist there. Our single natural satellite is dry as a
bone, but there is some evidence that small amounts
of water ice might reside in the permanently
shadowed craters near the Moon’s poles.
44
TheSkyX First Light Edition User Guide
To locate the Moon, on the Edit menu, click the
Find command, enter the name “moon” in the Find
text box, then click the Find Now button.
***
The “Classical” Planets
Not counting Earth, five planets are visible to the
naked eye. It has been known since ancient times
that the planets slowly change position relative to
the stars, which appear to be fixed, never moving
with respect to each other from year to year. In
fact, the word planet derives from an ancient Greek
term that means “wanderer.”
All planets in our solar system orbit the Sun (you
probably know that the Sun is a star, not a planet).
Their orbits lie more or less in the same plane, so as
they circle the Sun, their paths are restricted to a
narrow band in our sky, which is called the ecliptic.
The constellations that lie in this plane received
special attention from ancient astronomers.
Collectively they are known as the Zodiac
constellations.
The farther a planet is from the Sun, the longer it
takes to complete a single orbit. Planets farther
from the Sun therefore move more slowly through
the Zodiac.
TheSkyX can locate any planet wherever it happens
to be on a given night. Below we describe some
general features of the planets, starting from the
closest in, then moving out to the edge of the solar
system.
45
Mercury
Mercury is the closest planet to the Sun. It takes
only 88 days to travel around the Sun once. This is
another way of saying that a year on Mercury is 88
days long.
Because Mercury is so close to the Sun, it can only
be spotted shortly after sunset and shortly before
sunrise, when it is near the “edge” of its orbit from
our perspective. It is hard to see much surface
detail on Mercury in even the most powerful
telescope, but the Mariner 10 spacecraft made three
“fly-bys” of Mercury in 1974 and 1975. Pictures
from that spacecraft revealed Mercury strongly
resembles our Moon, with a heavily cratered
surface. It is comparable to our Moon in size, but
much more dense. Being so close to the Sun, the
surface of Mercury is very hot, as you would
expect. The average daytime temperature there is
above 400º C.
Venus
Commonly known as both the morning and the
evening “star,” Venus is the brightest natural object
in the sky after the Sun and Moon. Its beautiful
radiance has dazzled mankind throughout history.
Venus is so bright that, from a very dark location, it
can cast shadows.
When astronomers first eyed Venus through
telescopes, they discovered that the planet is
perpetually enveloped in clouds. They never part,
keeping the surface of the planet forever shielded
from direct view. This fact led to a great deal of
fevered speculation about what might be hidden
46
TheSkyX First Light Edition User Guide
beneath those relentless clouds. Could Venus
harbor steamy, tropical rainforests, inhabited by
alien dinosaurs or even more exotic forms of life?
Much to the disappointment of science fiction
writers, astronomers discovered in the early 1960’s
that the surface temperature of this deceptively
serene-looking planet is hot enough to melt lead.
Venus is a hellish, uninhabitable desert. The reason
for this is a runaway greenhouse effect. The
Venusian atmosphere is almost entirely carbon
dioxide (CO2), a gas notorious for its effectiveness
at trapping heat. The fact that high concentrations
of CO2 have raised the surface temperature of
Venus so far above what we would otherwise
expect is one reason some worry about rising CO2
levels on our planet. If Venus had the same mix of
nitrogen and oxygen in its atmosphere as we have in
ours, it would almost certainly be a lovely place to
spend your vacation.
When Galileo began to systematically observe
Venus with his telescopes, he discovered it goes
through phases like the Moon.
This helped
convince him that the Sun, not the Earth, is the
center of motion in the solar system. Venus, like
Mercury, is an “inner” planet, meaning that they lie
closer to the Sun than we do. This is why these
planets are visible only in the early evening or predawn skies – from our location in the solar system,
they never appear to travel very far from the Sun.
Earth
Earth is the third planet from the Sun. Scientists
sometimes refer to Earth as the Water Planet
because more than 70 percent of our surface is
47
covered by liquid water, and water is essential for
life. Our world is the only planet in the solar
system that can support life as we know it.
A day is defined as the amount of time it takes for
Earth to make one complete rotation on its axis. A
year is defined as the time it takes Earth to make
one complete orbit of the Sun. The length of a day
and year are different on other planets because they
rotate at different rates and have different orbits.
The axis about which our planet turns is tilted
relative to the plane of our orbit. This is why we
have seasons.
In the summer, our northern
hemisphere is tilted toward the Sun, so the days are
longer, and sunlight strikes the Earth more directly,
making the northern hemisphere warmer (the
opposite is true in the southern hemisphere) than it
is in winter. In the wintertime, our northern
hemisphere is tilted away from the Sun. The days
are thus shorter and colder (again, the opposite is
true in the southern hemisphere).
A solstice occurs when our axis is tilted directly
toward or away from the Sun. The winter solstice is
the shortest day of the year, and the summer solstice
is the longest (depending on your latitude, this may
or may not correspond to the times of earliest
sunrise and latest sunset – the explanation is a little
more complicated than what we’re prepared to
discuss here).
An equinox occurs when the center of the Sun is
directly above the Earth’s equator. There are two of
these each year, one in spring (the vernal equinox)
and one in fall (the autumnal equinox). Equinox is
48
TheSkyX First Light Edition User Guide
derived from Latin and means “equal night.”
During an equinox, night and day are both just
about 12 hours long.
Like all planets, the orbit of the Earth is not
perfectly circular, but slightly elliptical. The Earth
is about a million kilometers closer to the Sun in
December than June.
Mars
The next planet out from the Sun is Mars. It is
about half the size of our planet and takes a little
more than two years to go around the Sun once.
Mars is very similar to Earth in two important ways.
Its day is just over 24 hours long, and its axis of
spin is tilted about 23 degrees, almost exactly the
same tilt as Earth. This means that Mars has
seasons, just like we do. But they last twice as long,
since a Mars’ year is about twice as long as one of
ours (687 Earth days, to be more precise).
Like Venus, the atmosphere of Mars is almost
entirely CO2. Unfortunately it is an extremely thin
atmosphere, about 1/100th the pressure of our
atmosphere at the equivalent of Martian sea level.
During the day, the surface temperature of Mars
near the equator can rise above freezing, but that
same night it will drop well below –100º C. A little
more greenhouse effect on Mars would be a
welcome thing. As it is, the air on Mars is too thin
to support liquid water on its surface, another blow
to all those science fiction writers who imagined
alien beings and ancient civilizations on Mars.
Still, Mars is the only other planet in our solar
system whose surface is directly accessible to
49
astronauts. Even though liquid water can’t exist on
Mars today, there is lots of geological evidence to
suggest that in the distant past, the atmosphere of
Mars was much thicker, and water flowed there
freely. This gives scientists hope that Mars may
have once harbored simple forms of life. If life did
thrive there in the distant past, it may still survive
today, perhaps in small “oases” deep underground,
where organisms would be protected from the harsh
conditions on the surface.
The best time to look at Mars in a telescope is
during an opposition. About every 26 months, Mars
and Earth line up on the same side of the Sun. This
is when Mars is at its brightest and closest, and
therefore appears at its best in a telescope. TheSkyX
can calculate the dates of future oppositions and
even tell you how large, in arc seconds, the disk of
Mars will appear in an Earth-bound telescope.
As Mars approaches opposition, it briefly exhibits
retrograde motion. This is a fancy way of saying
that Mars looks like it turns around and moves
backward in the sky for several days. This is
simply a trick of perspective. As our two planets
orbit the Sun, Earth catches up to and passes Mars.
When we pass, Mars appears to move backward
with respect to the far more distant stars.
Looking at Mars through a telescope, the first thing
an observer usually notices on the disk of the planet
are the albedo features. These are bright and dark
markings that mostly correspond to variations in the
coarseness of Martian surface dust. They were first
systematically charted and named by the Italian
astronomer Giovanni Schiaparelli in the 19th
50
TheSkyX First Light Edition User Guide
century. He mistakenly believed that the dark
features were seas and lakes, and he used the Latin
terms mare and lacus accordingly. Today we know
there is no surface water on Mars, but like Earth, the
Red Planet does have polar caps. Unlike our polar
ice, they are made not just of frozen water but
carbon dioxide or “dry ice” as well. During an
opposition, you can usually glimpse either the
northern or southern cap in a small telescope.
There is a huge difference between seeing Mars in a
telescope and looking at images of Mars taken by
orbiting spacecraft. Beginning with the Mariner 4
fly-by in 1965, American, Russian, and European
spacecraft have revealed Mars to be a world of
geological wonders.
Huge craters, towering
volcanoes, and immense systems of canyons mark
and etch its surface.
Mars is orbited by two small moons, named Phobos
and Deimos (ancient Greek words for fear and
terror, respectively). They are much smaller than
our Moon, irregularly shaped, and difficult to see in
most amateur telescopes. Some scientists believe
these moons are actually wayward asteroids.
The Asteroid Belt
A ring of interplanetary debris circles the Sun
between the orbits of Mars and Jupiter. These
rocky fragments are thought to be remnants from
the original disk of material that formed the planets.
The gravity of Jupiter prevented these bodies from
aggregating into a planet in their own right. There
are literally millions of asteroids, but collectively
their mass is only about 1/10 the mass of our Moon.
51
Ceres is the largest asteroid, and the first to be
discovered back on New Year’s Day in 1801.
Jupiter
Jupiter is the king of the planets. Ten times wider
than Earth, it has more mass than all of the other
planets in our solar system combined. Nearly a
billion kilometers from the Sun, it takes twelve
years to complete a single orbit.
Jupiter has a family of dozens of moons of various
sizes and shapes, forming, in effect, a “mini” solar
system. At last count, astronomers have charted
over 60 moons orbiting this giant world. Many of
these bodies are small as a typical asteroid (some of
them might even be asteroids that were captured by
Jupiter, caught like flies in its gravitational web).
Jupiter is attended by four large moons comparable
in size to our own Moon. Because they were
discovered by Galileo when he first turned his
telescope on Jupiter in 1609, we call them the
Galilean satellites.
TheSkyX includes telescope and spacecraft images
of Jupiter, and can plot the orbits of its Galilean
satellites. This is a particularly useful feature if you
have a telescope. The moons shift position night to
night as they orbit Jupiter, and you can track these
motions with a modest telescope, or even a good
pair of binoculars. Also, when a Galilean moon
passes in front of Jupiter, it casts a shadow on the
disk of the planet that can be observed in small
telescopes. These shadow transits are fascinating to
observe, and TheSkyX can tell you when they will
occur.
It also provides timings for another
52
TheSkyX First Light Edition User Guide
interesting phenomenon involving Jupiter’s moons,
an occulation. These occur when one of the moons
enters the giant planet’s shadow and passes behind
it. Interesting Historical Note: by timing the
occulations of the Jovian moon Io, the astronomer
Ole Romer was able to make a rough estimate of the
speed of light way back in 1676.
Saturn
Author’s comment: I’ll never forget the first time I
saw Saturn through a telescope. I was 11 years old.
The telescope was small enough to fit in a lunchbox,
but it was made by an extraordinary man named
Max Bray, and was more than a match for Saturn.
In the eyepiece, I saw a small white disk nestled
inside a perfect set of white rings. It took my breath
away. Everyone I know who has ever seen Saturn
in a telescope remembers it. The most fun I’ve ever
had in over three decades of being involved in
astronomy is showing someone Saturn in a
telescope for the first time. The planet is best
known of course for its extraordinary rings.
Saturn takes nearly 30 years to complete one orbit
around the Sun. During this period, our view of the
rings is slowly changing. Sometimes they are
spread relatively wide and are easy to see, but about
every 15 years they line up edge-on to our view.
These “ring plane crossings” last a few days or so,
and during this time all that can be seen of the rings
is a dark, thin line crossing the disk of the planet.
Like Jupiter, Saturn is attended by numerous moons
of various shapes and sizes. Titan, the largest, has a
mostly–nitrogen atmosphere about one-and-a-half
times thicker than the Earth’s.
53
But Wait – There’s More
Saturn is the farthest planet that was known to man
in ancient times. The invention of the telescope
revealed innumerable new worlds never before seen
by human eyes, including previously unknown
planets in our own solar system.
Uranus
The seventh planet out from the Sun, Uranus is the
first planet discovered by telescope.
The
astronomer William Herschel is credited with
recognizing it as a planet over two hundred years
ago, in 1781 (other astronomers had seen it, but
mistook it for a star – Herschel initially thought it
was a comet). Like Jupiter and Saturn, it is a giant,
much larger than Earth, and its atmosphere is
mostly made of hydrogen and helium. But there are
also significant amounts of water, ammonia, and
methane ice in this frigid world, and so astronomers
refer to it as an Ice Giant.
At a distance of almost 3 billion kilometers, Uranus
takes 84 years to make a complete trip around the
Sun. Its axis of rotation is tilted 98 degrees to the
plane of its orbit, as if the planet had been flipped
on its side. Like all of the giant planets, Uranus has
an extensive family of moons, at least 27. They are
named after characters taken from the works of
Shakespeare and Alexander Pope. The largest,
Titania, is about half the size of Earth’s Moon.
On a dark, moonless night, Uranus is just barely
visible to the naked eye – if you have very sharp
vision and know exactly where to look. TheSkyX,
54
TheSkyX First Light Edition User Guide
of course, can tell you where to find it. Uranus is
relatively easy to find in a good pair of binoculars.
Neptune
The next planet out, Neptune is similar in size and
composition to Uranus. It is also considered an Ice
Giant. The existence of Neptune was predicted by
mathematical analysis of the orbit of Uranus.
Deviations in the predicted orbit of Uranus led
astronomers to believe that some other large body
farther out in the solar system periodically tugs at
Uranus. This theory was confirmed when Neptune
was discovered close to its predicted position.
In a telescope, Neptune appears cool blue in color.
It was first spotted by none other than Galileo, when
it happened to be near Jupiter in the sky, but Galileo
assumed that this faint blue object was a star, not a
planet, and so he is not credited with its discovery.
It takes Neptune over 184 years to make a single
orbit of the Sun. Discovered in 1846, it has yet to
make a single orbit since it was first recognized as a
planet. It lies some 4.5 billion kilometers from the
Sun, and is attended by 13 diverse moons. The
largest, Triton, is 2,700 kilometers in diameter, just
a little smaller than our own Moon. Triton orbits
Neptune in a retrograde orbit, which means that it
travels backwards relative to the direction of
rotation of Neptune itself. This suggests that Triton
did not form with Neptune, but came into being
somewhere farther out in the solar system and was
later captured by Neptune’s gravity.
55
Pluto and the Ice Dwarfs
We all used to be taught that there are nine planets
in the solar system. That is no longer the case.
Pluto has been demoted. Today it is not considered
a full-fledged planet, but an ice dwarf, one of
perhaps hundreds of such objects that inhabit the
outer reaches of the solar system.
Many people, including a lot of astronomers, are
unhappy that Pluto has lost its status as a planet.
Controversy is still raging over the decision to
reclassify it. If you’re wondering who gets to
decide whether or not Pluto is a planet, the authority
rests on a group called the International
Astronomical Union (IAU). Founded in 1919, the
IAU has some 10,000 members, all professional
astronomers. Its main purpose is to promote and
protect the science of astronomy internationally, but
it also has sole authority for classifying and naming
astronomical objects. Despite some groups that
claim otherwise, you cannot have a star named after
yourself or a loved one without going through the
IAU.
During their August, 2006 meeting, the IAU
membership voted on a new, more rigorous
definition of a planet that had been developed by
one of its working groups. This new and improved
classification scheme included the category “dwarf
planets” to cover objects in our solar system that
had recently been discovered beyond the orbit of
Pluto. Unfortunately for Pluto fans, it perfectly fits
the new category, hence the demotion.
56
TheSkyX First Light Edition User Guide
Land of the Comets: The Kuiper Belt and the Oort
Cloud
One of the most beautiful things you’ll ever see in
the sky is a bright comet. Comets are refugees from
the outer fringes of the solar system. Mixtures of
ice and dust, the astronomer Fred Whipple famously
described comets as “dirty snowballs.”
Astronomers believe that most comets spend their
lives in either the Kuiper Belt or the Oort Cloud.
Named for the astronomers who first theorized their
existence, these regions of space, far beyond the
orbit of Pluto, are thought to be repositories of
matter left over from the formation of the solar
system.
A gravitational nudge from a nearby star or a
passing cloud of interstellar dust can send an object
from this region careening into the inner solar
system. When a comet gets close to the Sun, its ice
begins to sublimate. The escaping gas and dust
form the coma and tail that give comets their
distinctive appearance.
Most comets are unexpected strangers to our part of
the solar system, but some have settled into
predictable, short-term orbits. Halley’s Comet is
probably the most famous example. TheSkyX charts
the orbits of several periodic comets. Most of them
can only be seen on rare occasions with a telescope,
but you never know when a new comet will be
discovered and grace our sky in spectacular fashion,
as comets Hyakutake and Hale-Bopp did in the late
1990’s.
***
57
Beyond the Backyard: Our Home Galaxy
Our Sun is but one member of a huge assemblage of
hundreds of billions of stars that comprise our home
galaxy, the Milky Way. Our galaxy is also
peppered with vast, colorful clouds of gas and dust,
called nebulae, and other exotic objects.
The invention of the telescope revealed that there is
much more in the night sky than stars and planets.
In the 18th century, the French astronomer Charles
Messier began to catalog some of these mysterious
objects to make sure he didn’t mistake them for new
comets. The Messier Catalog is still in use today.
It includes star clusters, and various kinds of
nebulas and galaxies. These so-called “deep sky”
objects are favorite viewing targets of amateur
astronomers.
There are literally millions of objects in the sky that
astronomers want to keep track of.
Various
catalogs have been developed for this purpose.
TheSkyX includes several of them in order to chart
these objects on the Sky Chart.
The Milky Way
The ancient Greeks believed that the Milky Way
was exactly that: spilled milk. History failed to
record whether anyone cried over it. It wasn’t until
Galileo invented the astronomical telescope that the
true nature of the Milky Way was revealed: millions
of stars too distant to be resolved by the naked eye.
We now know that the stars of our particular galaxy
form an immense pinwheel shape, with several
spiral arms extending out from its center. When
58
TheSkyX First Light Edition User Guide
you look at the Milky Way, you’re looking at a
section of one of these spiral arms (galaxies come in
a variety of shapes and sizes, from spherical to
irregular – more on this later).
An unfortunate fact of modern life is that the Milky
Way is too faint to be seen from within cities and
most of their suburbs. You need to be far from city
lights and any other source of light pollution to
appreciate how extraordinarily beautiful it is.
TheSkyX can display the Milky Way at various
levels of brightness, simulating what you might see
from the outskirts of a small town or an isolated
mountain peak. Astronomers have come up with
the very cool-sounding term isophote to describe
regions of equal brightness in the Milky Way.
***
Beyond Our Galaxy: The Great Big Universe
Out There
About a hundred years ago astronomers believed
that our galaxy, the Milky Way, contained pretty
much everything in the universe. But as telescopes
became larger and more powerful, it became clear
that there are other galaxies beyond the Milky Way
– lots of them, in fact. According to the latest
estimates, there are some fifty to one hundred
billion galaxies in our universe comparable in size
to the Milky Way.
Our galaxy is also surrounded by a halo of some
hundred and fifty star clusters. These clusters
contain hundreds of thousands to millions of stars
arranged in relatively compact, spherical shapes.
These globular clusters are made up mostly of
59
ancient stars, some of them over ten billion years
old.
Just as some planets have moons, the Milky Way
and many other galaxies are orbited by smaller
“satellite” galaxies. The Milky Way has at least
two. They were originally described by Persian
astronomers, but today we call them the Magellanic
Clouds in honor of Ferdinand Magellan, a 16th
century European explorer who observed and
charted them on one of his epic voyages into the
Southern Hemisphere. Our galactic companions are
most easily seen from that hemisphere, although at
certain times of year they can be glimpsed from
very low Northern latitudes. They are beautiful
objects, and to the naked eye look like small shreds
of the Milky Way. Even though they lie only 20
degrees apart in the sky, they are separated by
75,000 light years in space. With a telescope you
can resolve some of their stars, and also see nebulae
and star clusters that reside within them.
The Milky Way is just one of billions of galaxies
that populate the Universe. Besides the Magellanic
Clouds, only one of these other galaxies is visible to
the naked eye. It’s called the Andromeda Galaxy
because it lies within the boundaries of that
constellation. Every other galaxy requires a good
pair of binoculars or a telescope to see.
TheSkyX’s database includes thousands of galaxies
within reach of amateur telescopes. They can be
displayed in the Non-stellar Objects section of the
Chart Elements menu.
60
TheSkyX First Light Edition User Guide
Galaxies of various shapes and sizes exist right out
to the edge of observable space. We live in a truly
extraordinary universe. We hope the TheSkyX will
enrich and expand your appreciation of it.
***
What’s Up? – A Closer Look
With all the objects “up there” which ones are best
to look at tonight? The Tools > What’s Up Setup >
What’s Up button makes answering this question a
bit easier.
By default, each time the What’s Up button is
clicked, the Observing List window presents a list
of the most interesting objects that are visible to the
naked eye for the current time.
Select an object in the list to view observing notes
on the object. To view detailed information about
the object, click the Find window on the Display
menu. To view its photo (if there is one available)
or an H/R (Hertzsprung-Russell) Diagram for stars
in the Hipparco/Tycho catalog, click the Show
Photo Viewer in the Photos window.
The selected object can be centered on the Sky
Chart by selecting the Center and Frame command
from the Show on Sky Chart popup menu.
Here’s a neat feature: Select the first item in the
What’s Up list. Next, on the Show on Sky Chart
pop-up menu, select Naked Eye View, then use the
down arrows on the keyboard to scroll through the
list. Notice that the Sky Chart is updated to show a
61
green laser pointer indicating position of each
object.
What’s Up? Setup
Use the Tools > What’s Up Setup command to
configure your viewing time (current time, morning,
evening or midnight) and what optical aid you’ll be
using (naked eye, binoculars or small telescope).
The Interesting Objects (Top Ten) option finds
what the authors believe are the best objects or
events to view.
You can also filter which types of objects you want
to view. Once you’re done, click the What’s Up?
button to update the report.
***
62
Index
3D stars, 39
absolute magnitude, 34
albedo, 50
altitude, 25
analemma, 15
apparent magnitude, 34
Asteriod Belt, 51
asteriods, 40
asterisms, 36
aurora australis, 42
aurora borealis, 42
azimuth, 25
calendar, 18
celestial equator, 24
comets, 39, 57
Command Center, 14
constellations, 34
date & time, 20
date and time, 19
declination, 24
Deimos, 51
Disclaimers, 3
double star
binary, 30
dwarf planets, 56
Earth, 47
eclipsing binaries, 32
ecliptic, 45
equinox, 48
export
star charts, 37
field of view, 21, 22
field width, 22
find
objects, 43
planets, 43
fireball, 40
galaxies, 58
globular clusters, 59
Hipparco/Tycho stellar
catalog, 61
ice dwarfs, 56
Ice Giant, 54
images
celestial objects, 16
information
about an object, 18
International Astronomical
Union (IAU), 56
isophote, 59
Jupiter, 52
location, 14
location on Earth, 14
logarithmic scale, 27
Magellanic Clouds, 60
magnitude, 27
absolute, 34
apparent, 34
filtering by, 39
mare, 44
Mars, 49
Mercury, 46
meridian, 25
meteor, 39
radiant, 41
showers, 41
meteorites, 40
iron, 40
stony, 40
Milky Way galaxy, 38, 58, 60
minor planets, 40
Moon, 43
naked eye, 23
nebulas, 58
Neptune, 55
night vision, 38
nuclear fusion, 32
Oort Cloud, 57
orientation commands, 20
Phobos, 51
Photo Viewer, 17
photographs, 16
photos, 16
pictures, 16
planets, 45
Pluto, 56
printing charts, 37
radiants
meteors showers, 42
red screen, 38
retrograde motion, 50
right ascension, 24
Saturn, 53
save command, 15
seasons, 48
sky chart, 14
small solar system bodies
comets, 57
pluto, 56
solstice, 48
spectral class, 33
star names, 26
sunset, 19
tours, 15
transit time, 25
twilight, 19
uninstall, 13
Uranus, 54
variable stars, 32
Venus, 46
What’s Up Tonight?, 17
Zodiac, 45
zoom
in, 22
out, 22
zoom box, 23
64
NEXSTAR+ HAND CONTROL
~CELESTRON.
Congratulations! You have received a newly upgraded NexStar+ hand control with your telescope.
The NexStar+ hand control features all of the functionality of the older NexStar hand control but offers the
following improvements:
• Expandable functionality through the use of the Help and Option buttons [available in future firmware updates]
• LCD is Less sensitive to low temperatures
• Directional buttons have raised edges to make them easier to find without Looking at the hand control
• Support for faster updating via Celestron's new firmware management software
Below is a brief description of the individual components of NexStar+ hand control.
1. LIQUID CRYSTAL DISPLAY (LCD) WINDOW: Offers
improved performance in cold weather and red backlighting for
comfortable nighttime viewing of telescope information
and scrolling text.
2. ALIGN: Instructs the telescope to begin the default alignment
procedure. It is also used to select star or object as an
alignment position.
3. DIRECTION KEYS: Allow complete control of your telescope
in any direction. Use the direction keys to center objects in
the eyepiece or to manually slew your telescope.
4. CATALOG KEYS: Allow direct access to each of the main
catalogs in the database of thousands of objects.
Your telescope contains the following catalogs in its database:
•Solar System -All 7 planets in our Solar System plus the Moon,
Sun and Pluto
•Stars - Custom lists of all the brightest stars, double stars,
variable stars, constellations and asterisms
•Deep Sky- Custom lists of all the best Galaxies, Nebulae
and Clusters, as well as the complete Messier and select
NGC objects
5. IDENTIFY: Searches your telescope's database and displays
the name and offset distances to the nearest matching objects.
6. MENU: Displays setup and utilities functions, such as
tracking rate and user defined objects and others.
7. OPTION (CELESTRON LOGO): Works similar to the SHIFT key
on a keyboard and can be used in combination with other keys to
access more advanced features and functions to be added with
later firmware updates.
8. ENTER: Pressing ENTER allows you to select any of your
telescope's functions, accept entered parameters and slews
the telescope to displayed objects.
9. BACK: Similar to the UNDO button on the original hand
control, pressing BACK will take you out of the current menu
and display the previous level of the menu path. Press BACK
repeatedly to get back to a main menu or use to erase data
entered by mistake.
10. SKY TOUR: Activates the tour mode, which seeks out all
of the best objects in the sky and automatically slews your
telescope to those objects.
11. SCROLL KEYS: Used to scroll UP and DOWN within any of
the menu lists. A double arrow symbol on the right side of the
LCD indicates that the scroll keys can be used to view additional
information. The buttons have an angled shape to make it easier
to locate without looking.
12. MOTOR SPEED: Similar to the Rate Button on the original
NexStar hand control, it allows you to change the motor's speed
when the direction keys are pressed .
13. OBJECT INFO: Displays coordinates and valuable information
about objects selected from your telescope's database.
14. RS-232 JACK: For use with computer software programs for
point and click slewing capability and updating firmware via PC.
15. HELP MENU: In future firmware updates, this button will offer
troubleshooting tips. For your convenience, it currently functions
as a shortcut to the Messier Catalog.
NexStarf NEXSTAR+ HAND CONTROL
':~
SELECTING AN OBJECT
Once the telescope is properly aligned, you can choose an object
from any of the catalogs in t he NexStar+ hand control's database.
The hand control has a key designated for each category of
objects in its database; Solar System objects, Star s and Deep
Sky objects.
• Solar System- The Solar System catalog will display all of the
planets (and Moon] in our Solar System that are currently visible
in the sky. To allow the Sun to be displayed as an option in the
database, see Allow Sun option in the Database Setup section of
the manual.
• Stars- The Stars catalog displays custom lists of all the
brightest stars, double (binary] stars, variable stars,
constellations and selected asterisms.
• Deep Sky- The Deep Sky catalog displays a list of all of the best
Galaxies, Nebulae and Clusters, as well as the complete Messier
and select NGC objects. There is also an alphabetical list of all
deep sky objects in order by th eir common name.
Use t he SCROLL keys to scroll t hrough th e cata logs to find th e
object you wish to view.
When scrolling through a long list of objects, holding down either
the UP or DOWN key will allow you to scroll through the catalog
at a rapid speed .
SLEWING TO AN OBJECT
Once th e desired object idisplayed on the hand control screen,
you have two options:
• Press the OBJECT INFO Key. This will give you useful
information about the selected object such as magnit ude,
constellation and extended inform ation about th e most
popular objects.
o Use t he UP/DOWN arrow buttons to scroll through the
displayed object info
o Use the BACK button to return to t he object database
MOTOR SPEED BUTTON
The MOTOR SPEED button, sim ilar to the Rate button on the
original NexStar hand control, allows you to instantly change the
speed r ate of the motors from high speed slew rate to precise
guiding rate or anywhere in between. Each rate cor responds to
a number on the hand control key pad. The number 9 button is
the fastest rate (approximately 3.5° per second , depending on
the mount] and is used for slewing between object s and locating
alignment stars. The number 1 button on the hand control is the
slowest rate (half sidereal] and can be used for accurate centering of objects in the eyepiece.
To change the speed of the motors:
•Press the MOTOR SPEED key on the hand control.
The LCD will display the current motor speed
• Press the number on the hand control that
corresponds to the desired speed
The hand control has a "dou ble button " feature t hat allows you
to instantly speed up the motors without having to choose a
speed . To use this feature, simply press the arrow button that
corresponds to the direction that you want to move the telescope.
While holding that button down , press the opposite direction button . This wi ll increase the speed to the maximum slew rate.
Wh en using th e hand cont ro l's up and down direction buttons,
th e slower slew rates (6 and lower] move th e motors in th e opposite direction than the faster slew rates (7- 91. This is done so
that an object will move in the appropriate direction when looking into th e eyepiece (i.e. pressing the UP arrow bu tto n will move
t he star upwards in th e fi eld of vi ew of th e eyepiece]. However,
if any of the slower slew rates (rate 6 and below] are used to
center an object in th e StarPo inter, you may need to press the
opposite directional button to make the telescope move in the
correct direction.
• Press the ENTER Key. This will automati cally slew th e
telescope to th e coo rdin ates of the object displayed on
t he hand contro l. While t he telesco pe is slewin g to t he
object, the user ca n still access many of th e ha nd co ntrol
funct ions (such as displayi ng information about t he object].
NOTE: The Messier, NGC and SAO catalogs require th e user
to enter a numer ic designation. Once you have selected the
appropriate catalog button and selected the Messier , NGC or
SAO catalog, you will see a flashing cursor indicating you are
in numeri c entry mode.
THEHANDCONTROLMENU
The "Hand Control" menu allows you to customize certain features of the NexStar+ hand control. To access this menu, press the MENU button (#7 on the
keypad) and use the scroll buttons to select "Hand Control" and press ENTER.
Use the scroll buttons to select fromthe following options:
Lights Control: Independently adjust the brightness of the number keypad
and the LCD.
o Scrolling Menu: Adjust how fast words move across the face of the LCD.
o Toggle Bold Font: Change the format of the font displayed on the LCD
Enter t he catalog number for the object you want t o vi ew . .
from normal to boldface.
Press ENTER to co mmand the telescope to slew to the object,
o Set Contrast: Use the scroll keys to adjust the contrast of the LCD.
or hold th e OPTION button (the Celest ron logo] and press
o Set Language: Change the displayed language on the LCD.
o
OBJECT INFO to see infor mati on about the object you selected.
Caution: Never slew the telescope when someone is
looking into the eyepiece. The telescope can move at
fast slew speeds and may hit an observer in the eye.
NOTE: The Set Language feat ure may also appea r th e first
tim e you use your new hand control. You may also initiate it
at any tim e by hol ding down t he Opti on button (the Celestron
logo] for 10 seconds wh ile powering up the telescope.
~CELESTRON.
2835 Columbia Street
TEL (310) 328-9560
I Torrance, CA 90503
I FAX (310) 212- 5835
www.celestr on.com
Copyright 2012 Celestron 1 All Rights Reserved.
NexStar Observer List
Installation Instructions
Linking to your NexStar Telescope
The NexStar has a RS-232 port located on the bottom of the hand control that allows it to communicate with the NexStar
Observer List software. Establishing a link with your NexStar will require the use of an optional RS-232 cable (#93920) available
through your local Celestron dealer. Before attempting to create a link with your computer, you must do the following:
1.
2.
Connect the RS-232 cable - Connect the phone jack end of the RS-232 cable to the port on the bottom of the hand
control and connect the 9-pin connector to the back of your computer.
Do a star alignment- Complete any of the star alignment procedures as described in the Instruction manual.
Installation
Very Important: If you currently have an older version of NexStar Observer List installed, you must uninstall it prior to
installing this new version. Go to the Start Menu, Control Panel, Add/Remove Programs and double-click NexStar Observer List.
If you are prompted whether you want to remove shared components, answer no. This will leave your current observation
lists and User Supplied Objects intact as well as other components that may be used by other programs in your computer.
To install NexStar Observer List Version 2, run the file Setup.exe on the NSOL CD.
Very Important: During the installation process, you may be presented with dialog boxes stating that the installation is trying to
replace an already existing file on your system and the existing file is newer. You will be asked if you want to keep the existing
file: answer YES. Many programs will present you with this option during installation and 99% of the time you should answer
yes to keep your existing file. Additionally, you may be presented with a dialog box stating that certain system files are out-ofdate on your computer and need to be updated to continue. These files have been updated by Microsoft and are needed to access
the database in NexStar Observer List. The updated files address security concerns that have been discovered in many Microsoft
products that access databases. If you wish to use NexStar Observer List you will need to allow the setup program to update these
files.
The first time you run the program (you will find it was added to Programs on the Start menu), you will be presented with the
operating instructions. Please take the time to read the instructions. After the instructions, you will be prompted for basic setup
information such as type of telescope, communication port the scope will be connected to, etc. Make sure that your Observing
Location and Altitude Control (slew limits) are the same as you entered into the hand control when you aligned the telescope.
If the program won't start after installing and your computer uses Windows 95 or Windows 98, look in the DCOM files on the CD
and double-click the DCOM file for your version of Windows. DCOM is a database patch for Windows that comes directly from
Microsoft£.
Uninstalling
If you decide to uninstall NexStar Observer List, simply open Control Panel on the Windows Start Menu, then open Add/Remove
Programs. Look for NexStar Observer List and double-click to remove. Very, very important: when you are prompted about
removing shared files, click the button “Remove None”. This will leave components that might be in use by other programs in
place and it will also leave any observing lists and the file containing your User Supplied Objects in your data folder (generally
C:\Program Files\NSObserverList\Data).
Technical Support
I provide support via email for any questions or problems you might have regarding NexStar Observer List. To contact me,
simply send an email to [email protected]. If you received an error message on the screen, please describe what you
where doing when you got the error, provide the full text of the error, and let me know if you can recreate the error. You may
also visit the NexStar Resource Site at www.angelfire.com/ns/nexstar and check the Downloads page for program updates.
Clear Skies and Happy Computing!
Mike Swanson
0505
NexStar Observer List
Version 2
Operating Instructions
If you are running the program for the first time, NexStar Observer List will start after
you close this window. If you do not wish to read these instructions now, you can view
them at any time you are in the program by pressing F1 or choosing "Operating
Instructions" from the Help menu.
__________________________________________________________
Introduction
NexStar Observer List (NSOL) allows you to create observing lists that are automatically saved
to the hard drive of your computer. You build the lists by choosing from tens of thousands of
deep-sky objects and stars. The NSOL database includes 39,179 objects:
x The entire Messier catalog (110 objects)
x The entire Caldwell catalog (109 objects)
x The entire NGC catalog (7,840 objects)
x The entire IC catalog (5,386 objects)
x The entire Abell catalog (4,076 objects)
x All 15 magnitude or brighter galaxies from the UGC catalog (6,009 objects)
x 10,381 stars organized by SAO number and HD number
x 5,268 double stars organized by SAO number and HD number
x And you can add as many additional objects as you wish!
NSOL allows you to more easily go to objects not in the NexStar database, such as objects you
learn about in magazine articles and books. You can create as many observing lists as you want
and you can exchange your lists via email with other NSOL users. Submit your favorite
observing lists to the author ([email protected]) and they will be posted on the NexStar
Resource Site (www.angelfire.com/ns/nexstar) for others to download and enjoy.
NSOL works with all models of NexStar GT telescopes (60/80/114/4) as well as the NexStar 5, 8
and GPS telescopes. Your computer must be running Windows 95/98/ME/NT or 2000 and have
at least 10MB of free hard drive space.
As with any Windows program, you will note that some menu items have shortcut keys listed,
such as Ctrl-N for creating a New List. Also, menus can be accessed by Alt and the underlined
letter in the menu name. The same goes for buttons in the screens you are working in, Alt and the
underlined letter performs the same action as clicking the button with the mouse.
__________________________________________________________
Operating the Program
Setup
The Setup options you are presented with when you first run the program can be found on the
"Tools, Setup" menu command. Most of the items are self-explanatory, but some might require
explanation.
"Use Windows Time Zone Setting?" allows the program to calculate the correct Universal Time
(UT) without you worrying about whether your location is currently observing Daylight Savings
Time or Standard Time. It will only work if you have set the correct time and selected the correct
time zone in Control Panel, Date/Time (you can also set this by double-clicking the time in the
lower right corner of the Windows screen). If your time zone is not available in Windows, you
will need to remove the check mark on this option and manually enter the number of hours you
are away from UT.
Observing Location is used with UT to calculate the current altitude of objects and to draw sky
charts. You do not need to be too precise; the observing location settings have absolutely no
effect on the accuracy of Goto operations. If you are within 100-150 miles of the correct settings,
you will hardly notice the difference.
The Altitude Controls settings allow you to prevent Goto operations below the minimum setting
and above the maximum setting. If you attempt a Goto outside of your limits, you will be
prompted and can then choose to override and Goto anyway. If you do not wish to receive these
warnings at all, remove the check mark next to Use Altitude Controls. Note that this feature is
especially useful when using the scope in equatorial mode as the altitude info on the scope's hand
controller is not local altitude, but rather the object's altitude at the North or South Pole. NexStar
Observer List will always show the local altitude.
The Location of Observer Lists option allows you to change the folder your observer lists and
User Supplied Objects database are stored in. This can be convenient if you are currently making
backups of a "My Documents" folder (or similar) and want to include your NexStar Observer List
data in the backup as well. You will need to create a separate folder in the "My Documents"
folder, perhaps named "NSOL Data". Then use this setup option to select that folder. Then exit
NSOL and using Windows Explorer, you should copy the files from the C:\Program
Files\NSObserverList\Data folder (the default data folder) into your newly created folder.
Caution: if NexStar Observer List cannot find the file NSObserverUserList.mdb (the User
Supplied Objects database) in the folder you selected, you will not be able to edit observer lists.
Hyper Hand Controller
A new feature in this version is the Hyper Hand Controller (HHC). This allows you to directly
access the entire NSOL database. You can open the HHC from the "Tools" menu or with the
button resembling a NexStar hand controller.
The HHC has four areas. The upper right portion of the window contains the eight lists of the
NSOL database. You access each list by clicking the tabs along the top. Each list also has a
search section that lets you search by Object Number or Common/Alternate Name (labeled
simply "Name" in the lists). While you might not mind scrolling down the Messier or Caldwell
lists, most of the other lists are very long and the search feature will be a big time saver. Note
that HD numbers for stars and double stars are found in the Common/Alternate Name field. Use
these lists to find the object you want to slew your telescope towards.
The Messier, Caldwell, NGC and IC lists (note that they are all on the same row of tabs) can also
be sorted by Object Number (the default), Constellation, Magnitude and Right Ascension. This
can be very useful to help you select items for viewing. You may find the Constellation sort
order to be most useful as it allows you to easily cover all objects in a specific area of the sky. To
select any of these sort orders, simply click once on the Number, Constellation, Magnitude or RA
column headings. Deep Sky, User Supplied, SAO Stars and Double Stars can be sorted by Object
Number (the default) and Right Ascension. RA can be useful when trying to match an object
whose name is uncertain - especially true of double stars.
One of the eight lists is different from the rest - the User Supplied Objects. Using the Edit button
to the left of this list, you can add, edit and delete items in this list.
Below the object lists is a section for quickly slewing to any desired Right Ascension and
Declination. Simply enter the coordinates and click the Quick Goto button. RA is entered with
hours in the first box and minutes in the second box. Dec is entered with degrees in the first box
and arcminutes in the second box - don't forget to change + or - if necessary. To enter
coordinates with seconds/arcseconds, you must convert them to decimal fractions of a
minute/arcminute and include them in the minutes/arcminutes box. The Seconds to Decimal
conversion boxes help to simplify this process. For example, if you want to enter 23m 34s, type
34 in the box under seconds and you will find this equates to 0.57. So, in the arcminutes box you
would enter 23.57.
After slewing to an object, you might be interested in checking the coordinates that the scope
landed at. To do this, you can click the Get Scope Position button at the top of the main window
or the bottom of the Hyper Hand Controller. This readout does not update automatically, to
refresh with the current scope position, click the button anytime.
In the upper left of the HHC, you are presented with a simple all sky chart. The object you
currently have selected from the lists to the right will be shown on the chart as a light blue oval, if
it is currently above the horizon. The sky chart is dependent upon the date, time and time zone
settings in Windows as described in the Setup section above.
In the bottom left of the HHC you will find full information for the item currently selected from
the lists on the right. The altitude is dependent upon the date, time and time zone settings in
Windows as well.
Creating Observer Lists
While the HHC lets you get a quick start using the NSOL database, the real power of NSOL is the
ability to organize your observing session. Prior to stepping outside, you can create an observing
list that will keep you on-track throughout the night. To get started, use either the "File, New
List" menu command or click the first button on the toolbar. You will be asked to name the list.
Choose something descriptive such as "Best objects for January". After typing the name and
clicking the Save button, you will be presented with a window that displays the observer list and
allows you to control your telescope. The list will be empty at first, so you should begin by
clicking the Edit List button.
After clicking Edit List, you will be presented with a window similar to the Hyper Hand
Controller that accesses the full NSOL database. The pane to the left is the list you are building,
while the right side of the window is comprised of the eight separate lists of the full database.
Each of the eight lists functions basically the same. First you find an object you wish to add to
your observer list and then you either click the <- button at the upper left corner of that list or you
can double-click the gray button at the left edge of the row for that object. This button is also
known as the row selector. This might sound a little confusing, but it's easier done than said!
Each list also has a search section that operates just as the Hyper Hand Controller described
above.
The sky chart on the left shows you the location of the object you have selected from your
observer list, or the object you have selected from the tables in the NSOL database. Note that it
defaults not to current date and time (unless it is between 1 and 6 AM), but rather 10 PM of
today's date. You can change the date and time of the sky chart with the <-- Change button. This
sky chart makes it easier to both organize the order of the items in your observer list as well as
insuring you select objects that will actually be above the horizon at your expected viewing time.
The Messier, Caldwell, NGC and IC lists (note that they are all on the same row of tabs) can also
be sorted by Object Number (the default), Constellation, Magnitude and Right Ascension. This
can be very useful to help you select items for viewing. You may find the Constellation sort
order to be most useful as it allows you to easily cover all objects in a specific area of the sky. To
select any of these sort orders, simply click once on the Number, Constellation, Magnitude or RA
column headings. Deep Sky, User Supplied, SAO Stars and Double Stars can be sorted by Object
Number (the default) and Right Ascension. RA can be useful when trying to match an object
whose name is uncertain - especially true of double stars.
You will also notice that below your object list, in the bottom left corner, there are four buttons:
x Close - Returns you to the main window.
x Move Up/Move Down - Use these to move objects up or down the list to put things in the
order in which you want to view them.
x Delete - Remove an object from the observer list.
One of the eight lists is different from the rest - the User Supplied Objects. Using the Edit button
to the left of this list, you can add, edit and delete items in this list. You can also edit the User
Supplied Objects after starting NexStar Observer List (no need to open an observer list) by using
the "Tools, Edit User Supplied Objects" menu command.
After you have added the items you want in the observer list, click the Close button to return to
the main window. Now you can see that the list window has three main sections. In the center is
the list itself. To the left is the full information for the currently selected object. To the right is
an all sky chart with the currently selected object shown as a small light blue oval. If you do not
want to edit the list further and you do not wish to observe the objects with your telescope at this
time, you would click the Close button. When you want to open one of the lists you have created
again later, use the "File, Open Existing List" menu command or the button with the yellow
folder. You can have up to eight lists open at the same time; the Window menu lets you switch
between all open lists. We will describe using this list to control your telescope later in the
instructions.
Printing an Observing List
To print an observing list, you must first have the list open. Refer to the directions above to open
an existing list. Use the "File, Print" menu command or the button with the printer. Then simply
choose whether you want a Compact List (prints the objects with a small amount of space
between each) or a List with Comment Area (prints the objects with room to write observing
notes after each). You can also select the number of copies you would like.
Alignment Star Chart
NSOL can also help you to locate your alignment stars. Use the "Tools, Alignment Star Chart"
menu command or the button with the star-studded black circle to display an all sky chart with
NexStar alignment stars designated. This feature is dependent upon the correct date, time and
time zone in Windows as described in the Setup section above. Note that you can turn off and on
the names of the alignment stars with the Toggle Names button.
Red Screen Mode
The last item that might need mentioning is the Red Screen mode. When observing at night, the
normal screen colors can ruin your night vision. To change the screen colors to a scheme more
friendly to dark-adapted eyes, use the "Tools, Red Screen" menu command, or click the button on
the toolbar with the red-lens glasses. To change back to a normal color scheme, repeat the above
process or, simply close the program. In the event this program or any other astronomy program
were to lock up or exit abnormally leaving you with a red screen, you can restore your normal
colors by right-clicking on the desktop (the screen background when no windows are visible) and
choosing properties. Then go to the Appearance sheet and choose the Scheme named Windows
Standard.
__________________________________________________________
Using the Program with Your Telescope
Caution: Just as when you are using the hand controller or any other program for slewing your
telescope, it is possible for the telescope to make contact with an immovable object - generally
the tripod or mount. For the N4, N5, N8 and GPS models, this is normally not a problem, unless
you are using an extra large diagonal or perhaps a camera. For the NexStar GT's, it is easy for the
telescope to make contact with the tripod. For these reasons you should monitor your scope
while in motion and be prepared to cancel the slew. Generally you can cancel a slew with any of
the direction buttons on the hand controller. Note that the Altitude Controls described in the
Setup section above can help to prevent this.
Note: The slew filters (minimum and maximum altitude) on the NexStar GT hand controller will
prevent NSOL and other programs from slewing to an object outside of the slew limits. If your
scope does not move after sending a goto command, check the slew limit settings in the hand
controller.
When you are ready to use NexStar Observer List to control your telescope, setup and align your
telescope as you would normally. Remember the Alignment Star chart if you need help locating
two alignment stars. Connect the hand controller to the serial port of your computer and if your
model of NexStar has an RS-232 mode in the hand controller menu, you must enter that mode for
the telescope to communicate with NSOL. You can test whether your PC can communicate with
your scope by clicking the Get Scope Position button in the NexStar Observer List main window.
Next, open the Hyper Hand Controller to directly access items in the NSOL database or open the
observing list(s) of objects you wish to view. If you are using an observing list, the Next and
Previous buttons let you move through the list, or you can simply click on objects in the list on
the left. To slew the telescope to an object, check to be sure it is the current object - look for the
arrowhead in the row selector for that object or simply check the Current Object Info on the right.
Then click the Goto button. You can also slew to an object by double-clicking its row selector in
the list.
Note that if using an observing list (rather than the HHC) NSOL tracks the objects you have
attempted to goto with a "Y" in the Go column. You can clear one or all of the goto marks with
the Clear Go Marks button. Also note that you can track the objects you actually observed by
clicking the Observed button. You can clear the observed mark by clicking the Observed button
again - it simply toggles the "Y" on and off.
You can also issue a slew command for any Right Ascension - Declination using the Quick Goto
section at the top of the main window or the bottom of the Hyper Hand Controller. Simply enter
the coordinates and click the Quick Goto button. RA is entered with hours in the first box and
minutes in the second box. Dec is entered with degrees in the first box and arcminutes in the
second box - don't forget to change + or - if necessary. To enter coordinates with
seconds/arcseconds, you must convert them to decimal fractions of an minute/arcminute and
include them in the minutes/arcminutes box. The Seconds to Decimal conversion boxes help to
simplify this process. For example, if you want to enter 23m 34s, type 34 in the box under
seconds and you will find this equates to 0.57. So, in the arcminutes box you would enter 23.57.
After slewing to an object, you might be interested in checking the coordinates that the scope
landed at. To do this, you can click the Get Scope Position button at the tope of the main window
or the bottom of the Hyper Hand Controller. This readout does not update automatically, to
refresh with the current scope position, click the button anytime.
__________________________________________________________
Installation
Very Important: If you currently have an older version of NexStar Observer List installed, you
must uninstall it prior to installing this new version. Go to the Start Menu, Control Panel,
Add/Remove Programs and double-click NexStar Observer List. If you are prompted whether
you want to remove shared components, answer no. This will leave your current observation lists
and User Supplied Objects intact as well as other components that may be used by other programs
in your computer.
Very Important: During the installation process, you may be presented with dialog boxes stating
that the installation is trying to replace an already existing file on your system and the existing
file is newer. You will be asked if you want to keep the existing file: answer YES. Many
programs will present you with this option during installation and 99% of the time you should
answer yes to keep your existing file. Additionally, you may be presented with a dialog box
stating that certain system files are out-of-date on your computer and need to be updated to
continue. These files have been updated by Microsoft and are needed to access the database in
NexStar Observer List. The updated files address security concerns that have been discovered in
many Microsoft products that access databases. If you wish to use NexStar Observer List you
will need to allow the setup program to update these files.
After installation, you may delete the temporary folder with the installation files, however, I
recommend you keep a copy of the zip file.
The first time you run the program (you will find it was added to Programs on the Start menu),
you will presented with these operating instructions. Please take the time to read the instructions.
After the instructions, you will be prompted for basic setup information such as type of telescope,
communication port the scope will be connected to, etc.
If the program won't start after installing and your computer uses Windows 95 or Windows 98,
revisit the Downloads page on www.angelfire.com/ns/nexstar and download the DCOM patch.
__________________________________________________________
Uninstalling
If you decide to uninstall NexStar Observer List, simply open Control Panel on the Windows
Start Menu, then open Add/Remove Programs. Look for NexStar Observer List and double-click
to remove. Very, very important: when you are prompted about removing shared files, click the
button "Remove None". This will leave components that might be in use by other programs in
place and it will also leave any observing lists and the file containing your User Supplied Objects
in your data folder (generally C:\Program Files\NSObserverList\Data).
__________________________________________________________
Technical Support
I provide support via email for any questions or problems you might have regarding NexStar
Observer List. To contact me, simply send an email to [email protected]. If you
received an error message on the screen, please describe what you where doing when you got the
error, provide the full text of the error, and let me know if you can recreate the error. You may
also visit the NexStar Resource Site at www.angelfire.com/ns/nexstar and check the Downloads
page for program updates.
Clear Skies and Happy Computing!
Mike Swanson
Version 2.6.4c
For Windows
Control your
Celestron
Computerized
Telescope from
your PC and create
custom observing
lists from thousands
of deep-sky and stellar
objects.
For Windows
95/98/ME/NT/XP or 2000
Must have at least 1OMB
of hard drive space.
NexStar® SLT
~~.
../'0
~~
"'~<f
1')0
~
~es
Celestron • Torrance, CA 90503 U.S.A.
Tel: 310.328.9560 • www.celestron.com
q~e
~ws
C/ for ·
mdil/
\
'dual sale. It may on ':1
ce
~&
oe ?
u~c.X"'
/
