Celestron NexStar 102GT Instruction manual

Инструкция
Celestron
NexStar 102 GT 102x1000 AZ
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COMPUTERIZED TELESCOPE
INSTRUCTION MANUAL
TABLE OF CONTENTS
INTRODUCTION
Warning
ASSEMBLY
Assembling the NexStar
Attaching the Hand Control Holder
Attaching the Fork Arm to the Tripod
Attaching the Telescope to the Fork Arm
The Erect Image Diagonal
The Eyepiece
Focusing
The Star Pointer Finderscope
Star Pointer Installation
Star Pointer Operation
HAND CONTROL
Attaching the Computerized Hand Control
Powering the NexStar GT
The Computerized Hand Control
Computerized Hand Control Operation
Alignment Procedure
SkyAlign
Auto Two-Star Align
Two-Star Alignment
One-Star Align
Solar System Align
NexStar Re-Alignment
Object Catalog
Selecting an Object
Slewing to an Object
Finding Planets
Tour Mode
Constellation Tour
Direction Buttons
Rate Button
Set Up Procedures
Tracking Mode
Tracking Rate
View Time-Site
User Defined Objects
Get RA/DEC
Go to RA/Dec
Identify
Scope Setup Features
Setup Time-Site
Slew Limits
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COMPUTERIZED TELESCOPE
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COMPUTERIZED TELESCOPE
Filter Limits
Direction Buttons
Utility Features
Version
Light Control
Factory Setting
Get Alt-Az
Go To Alt-Az
Hibernate
Sun Menu
Scrolling Menu
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NEXSTAR MENU TREE
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TELESCOPE BASICS
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Focusing
Image Orientation
Calculating Magnification
Determining Field of View
General Observing Hints
CELESTIAL OBSERVING
Observing the Moon
Lunar Observing Hints
Observing the Planets
Planetary Observing Hints
Observing the Sun
Solar Observing Hints
Observing Deep Sky Objects
Terrestrial (Land) Viewing
Terrestrial (Land) Viewing Hints
Seeing Conditions
Transparency
Sky Illumination
Seeing
TELESCOPE MAINTENANCE
Care and Cleaning of the Optics
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APPENDIX A - TECHNICAL SPECIFICATIONS
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APPENDIX B – GLOSSARY OF TERMS
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APPENDIX C – RS 232 CONNECTION
38
APPENDIX D – OTHER RESOURCES
38
APPENDIX E – TIME ZONE MAPS
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SKY MAPS
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WARRANTY
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INTRODUCTION
COMPUTERIZED TELESCOPE
Congratulations on your purchase of the Celestron NexStar! 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 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 an experienced amateur, you will appreciate the comprehensive database of over 40,000 objects, including customized lists of all the best deep-sky objects, bright double
stars and variable stars. No matter 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:
Incredible 4°/second slew speed.
Fully enclosed motors and optical encoders for position location.
Computerized Hand Controller with over 40,000 object database.
Storage for programmable user defined objects.
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. This 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 using a safe 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.
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COMPUTERIZED TELESCOPE
The NEXSTAR 102GT// Refractor Telescope with Computerized Hand Control
1.
Objective Lens
7.
Accessory Tray
2.
Fork Arm
8.
Focuser Knob
3.
Power Outlet
9.
Erect Image Diagonal - 45˚
4.
Stainless Steel Tripod
10. Eyepiece
5.
Tripod Leg Extension Clamp
11. StarPointer Finderscope
6.
Computerized Hand Control
with Hand Control Holder
12. Optical Tube
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13. Dovetail Mounting Clamp
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ASSEMBLY
COMPUTERIZED TELESCOPE
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:
NexStar 102GT
Deluxe Accessory Tray
Eyepiece Kit - 1¼”
25 mm, 20 mm, 12.5 mm, 8 mm and 4 mm
Foam Lined Case
Battery Pack
45° Erect Image Diagonal - 1¼”
The SkyX First Light™ Astronomy Software
NexStar Hand Control with
40,000+ Object Database
StarPointer Finderscope
ASSEMBLING THE NEXSTAR
Your NexStar comes in three major sections: the optical tube, fork arm and the tripod. These sections
can be attached in seconds using the quick release coupling screw located under the tripod mounting platform. 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:
Flange Post
1. Remove the tripod from the box and spread the legs apart
until the center leg brace is fully extended.
Locking
Clips
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.
5. You will hear the tray snap into place.
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:
Locking Tabs
FIGURE 2-1
Bubble
Level
1. Loosen the tripod leg extension clamp (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. See Fig. 2-2
4. Tighten the tripod locking bolts to hold each leg in place.
FIGURE 2-2
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FIGURE 2-3
COMPUTERIZED TELESCOPE
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
into place. See Figure 2-3
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.
See Figure 2-4
FIGURE 2-4
Fork Arm Base
Tripod Mounting
Platform
Coupling Screw
Dove Tail Mounting Bar
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. Loosen the tube clamp tightening knob.
2. 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.
3. Tighten the tube clamp knob by hand to secure the tube to the
fork arm.See Figure 2-5
FIGURE 2-5
Your NexStar is fully assembled and is ready to attach the accessories.
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COMPUTERIZED TELESCOPE
THE ERECT IMAGE DIAGONAL
The diagonal diverts the light at a 45-degree 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 the tube. For daytime viewing, the diagonal uses an erecting prism
that allows you see land objects right-side-up to attach the diagonal:
1. 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.
2. Remove the protective dust cap from the focuser barrel.
3. Slide the chrome portion of the diagonal into the eyepiece adapter.
4. Tighten the thumbscrew on the eyepiece adapter to hold the diagonal in place.
5. If you wish to change the orientation of the diagonal,
loosen the thumbscrew on the eyepiece adapter until
the diagonal rotates freely. Rotate the diagonal to the
desired position and tighten the thumbscrew.
THE EYEPIECE
StarPointer
Eyepiece
Eyepiece Adapter
The eyepiece is the optical element that magnifies the
image focused by the telescope. The eyepiece fits either directly into the focuser or into the diagonal.
To install the eyepiece:
1. Loosen the thumbscrew on the diagonal so it does
not obstruct the inner diameter of the barrel.
2. Remove the protective dust cap from the
diagonal’s barrel.
3. Slide the chrome portion of the low power 25 mm eye
piece into the diagonal.
Focus Knob
Erect Image
Diagonal – 45˚
FIGURE 2-6 – VISUAL ACCESSORIES
4. Tighten the thumbscrew to hold the eyepiece in place.
5. To remove the eyepiece, loosen the thumbscrew on the diagonal and slide the eyepiece out.
Eyepieces are commonly referred to by focal length and barrel diameter. The focal length of each
eyepiece is printed on the eyepiece barrel. The longer the focal length (i.e., the larger the number) the
lower the eyepiece power or 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. The eyepiece adapter includes a fitting that
can be removed to allow 2” visual accessories to be used. Please note that eyepieces used directly in
the focuser without a diagonal may not achieve focus even when the focuser is extended to its maximum length.
FOCUSING
To focus your telescope, simply turn either of the focus knobs on the sides of the focuser see figure 2-6.
Turn the focus knob until the image is sharp. Once sharp, turn the knob towards you to focus on an
object that is closer than the one you are currently observing. Turn the knob away from you to focus
on a more distant object than the one you are currently observing.
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COMPUTERIZED TELESCOPE
THE STARPOINTER FINDERSCOPE
The StarPointer is the quickest and easiest way to point your telescope exactly at a desired object
in the sky. The StarPointer 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 StarPointer, simply move your telescope until the red dot, seen through the
StarPointer, 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 StarPointer comes equipped with a variable brightness control, two axes alignment control and
mounting brackets. Before the StarPointer is ready to be used, it must be attached to the telescope
tube and properly aligned: See Figure 2-7
Sight Tube
FIGURE 2-7 – STARPOINTER FINDERSCOPE
On/ Off
Brightnes Control
Azimuth
Adjustment Control
Battery Comapartment
(not shown)
Altitude
Adjustment Control
Dovetail Tightening Screws
Dovetail Mount
STARPOINTER INSTALLATION
1. Slide the StarPointer bracket into the dovetail
mounting platform on top of the focuser assembly.
See figure 2-8.
2. Orient the StarPointer so that the sight tube is facing
towards the front of the tube.
3. Secure the StarPointer bracket by tightening the
thumb screw on the mounting platform.
FIGURE 2-8– INSTALLING
STARPOINTER FINDERSCOPE
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COMPUTERIZED TELESCOPE
STARPOINTER OPERATION
The StarPointer is powered by a long life 3-volt lithium battery (#CR2032) located underneath the front
portion of the StarPointer. Like all finderscopes, the StarPointer 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 StarPointer. The alignment procedure is best done at
night since the LED dot will be difficult to see during the day. Note: Before using the StarPointer,
you must first remove the protective plastic cover over the battery. See Figure 2-9.
1. To turn on the StarPointer, rotate the variable brightness control See Figure 2-7.
clockwise until you hear a “click”. To increase the brightness level of the red dot,
continue rotating the control knob about 180º until it stops.
2. Locate a bright star or planet and center it in a low power eyepiece in the main telescope.
3. With both eyes open, look through the glass window at the alignment star.
4. If the StarPointer is perfectly aligned, you will see the red LED dot overlap the alignment star. If the
StarPointer is not aligned, take notice of where the red dot is relative to the bright star.
5. Without moving the main telescope, turn the StarPointer’s azimuth and altitude
alignment controls See Figure 2-7 until the red dot is directly over the alignment object.
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 StarPointer is now ready to be used.
Azimuth
Adjustment Knob
Protective
Cover
Battery
FIGURE 2-9
BATTERY COMPARTMENT
10
Red
Alignment
Dot
FIGURE 2-10
STARPOINTER FINDERSCOPE
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COMPUTERIZED HAND CONTROL
ATTACHING THE
COMPUTERIZED
HAND CONTROL
Computerized
Hand Control
Outlet
COMPUTERIZED TELESCOPE
Power Outlet
Battery Pack
The NexStar GT 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.
POWERING THE NEXSTAR GT
FIGURE 3-1 – THE NEXSTAR GT OUTLETS
The NexStar GT can be powered by the supplied battery pack or an optional 12v AC adapter. The
power pack requires 8 user supplied AA size alkaline batteries. To power the NexStar, insert the
batteries into the battery pack and plug the round post into the 12v outlet located on the side of the
fork arm. Once the battery pack is plugged in, the NexStar will power on and the red backlight on the
Hand Control display will come on.
In case of a loss of power, the optical tube can be moved up and down 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.
THE COMPUTERIZED HAND CONTROL
The NexStar GT’s Hand Controller is designed to give you instant access to all the functions the NexStar has to offer. With automatic slewing to over 40,000 objects and commonsense 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 GT Hand Controller:
1. 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.
2. Align: Instructs the NexStar to use a selected star or object as an alignment position.
3. Direction Keys: Allows complete control of the NexStar in any direction. Use the direction
keys to center objects in the StarPointer finderscope and eyepiece.
4. Catalog Keys: The NexStar has keys on the Hand Control to allow direct access to these
major catalogs in its 40,000+ object 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.
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COMPUTERIZED TELESCOPE
List – In addition, 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
Common name listing of the brightest stars in the sky.
Named Objects
Alphabetical listing of over 50 of the most popular
deep sky objects.
Double Stars
Alphabetical listing of the most visually stunning
double, triple and quadruple stars in the sky.
Variable Stars
Select list of the brightest variable stars with
the shortest period of changing magnitude.
Asterisms
A unique list of some of the most recognizable
star patterns in the sky.
CCD Objects
A custom list of many interesting galaxy pairs,
trios and clusters that are well suited for CCD imaging.
Abell Objects
A custom list of the Abell Catalog deep-sky galaxies.
IC Objects
A complete list of all the Index Catalog deep-sky objects.
Constellations
A complete list of all 88 constellations.
Tour
All the best objects for a given month and automatically
slews the NexStar to those objects.
5. INFO: Displays coordinates and useful
information about objects selected from the NexStar database.
6. 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 telescope control and
to update your NexStar’s firmware via PC.
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COMPUTERIZED TELESCOPE
COMPUTERIZED 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.
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.
”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.
SKYALIGN
SKYALIGN 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 SKYALIGN 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 40,000+ 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 SKYALIGN:
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 GT.” Press ENTER
to choose SKYALIGN. Pressing the ALIGN key will bypass the other alignment options and
the scrolling text and automatically begins SkyAlign.
2. Once SkyAlign 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.
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COMPUTERIZED TELESCOPE
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 Control’s 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. locations. 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 .
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
buttons (10) to toggle between options.
UP and DOWN scroll
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.
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.
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.
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COMPUTERIZED TELESCOPE
TIPS FOR USING SKYALIGN
Remember the following alignment guidelines to make using SkyAlign as simple
and accurate as possible.
> 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.
> 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.
> 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).
> Rarely SkyAlign will not be able to determine what three alignment objects were centered.
This sometime 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.
> Be sure to center the objects with the same final movements as the direction of the Go To
Approach. For example, if the scope normally finishes a Go To 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.
AUTO TWO-STAR ALIGN
As with SKYALIGN, 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. Once the NexStar is powered on, Press ENTER to begin alignment.
2. Use the UP and DOWN scroll keys to select Auto Two-Star Align and press ENTER.
3. 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 SkyAlign section for detailed instruction on entering time/site information).
4. 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.
5. 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.
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COMPUTERIZED TELESCOPE
6. 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:
> 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. Once the NexStar is powered on, use the UP and DOWN scroll keys to select
Two-Star Align, and press ENTER.
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.
HELPFUL HINT //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).
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.
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COMPUTERIZED TELESCOPE
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 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 Go To 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. Select Solar System 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 OBJECT” message will appear in the top row of the display. Use the UP and DOWN
scroll keys to select the daytime object (planet, Moon or Sun) you wish to align. Press ENTER.
4. 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.
5. 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.”
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COMPUTERIZED TELESCOPE
TIPS FOR USING SOLAR SYSTEM ALIGN
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 GT”
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.
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:
> 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. Select the desired star (or object) from the database and slew to it.
2. Carefully center the object in the eyepiece.
3. Once centered, press the UNDO button until you are at the main menu.
4. With “NEXSTAR GT” displayed, press the ALIGN key on the Hand Control.
5. The display will then ask you which alignment star you want to replace.
6. 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.
7. Press ALIGN to make the change.
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OBJECT CATALOG
COMPUTERIZED TELESCOPE
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:
> 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 allows you to scroll through the catalog to the desired object.
> 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”.
> 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.
SLEWING TO AN OBJECT
Once the desired object is displayed on the Hand Control screen, you have two options:
> 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.
> 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.
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COMPUTERIZED TELESCOPE
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:
> 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.
> 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.
> 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.
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 = 2x
6 = .5º / sec
2 = 4x
7 = 1º / sec
3 = 8x
8 = 2º / sec
4 = 16x
9 = 4º / sec
5 = 32x
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COMPUTERIZED TELESCOPE
RATE BUTTON
Pressing the RATE key 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:
> 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 GT, 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 StarPointer, 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.
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.
Note: The EQ North and EQ South tracking modes are only needed with telescopes that can
be polar aligned. The NexStar GT series are exclusively Alt-Az mounted telescopes and do
not require equatorial tracking.
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COMPUTERIZED TELESCOPE
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.
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 “GO TO SKY OBJECT”.
SAVE DATABASE (DB) 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.
SAVE LAND OBJECT:
ENTER RA - 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.
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COMPUTERIZED TELESCOPE
To go to any of the user defined objects stored in the database, scroll
down to either “GO TO SKY OBJ” or “GO TO 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.
GO TO 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 RA/DEC: Displays the right ascension and declination for the current position of the telescope.
GO TO RA/ DEC: Allows you to input a specific R.A. and declination and slew to it.
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:
> 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.
PRECISE GO TO
The NexStar has a precise Go To function that can assist in finding extremely faint objects and centering objects closer to the center of the field of view for high magnification viewing. Precise Go To
automatically searches out the closest bright star to the desired object and asks the user to carefully
center it in the eyepiece. The Hand Control then calculates the small difference between its go To
position and its centered position. Using this offset, the telescope will then slew to the desired object
with enhanced accuracy. To use Precise Go To:
> Press the MENU button and use the UP/DOWN keys to select “PRECISE GO TO.”
> Choose DATABASE to select the object that you want to observe from any of the
database catalogs listed
> Choose RA/DEC to enter a set of celestial coordinates that you wish to slew to.
> Once the desired object is selected, the Hand Control will search out and display
the closest bright star to your desired object. Press ENTER to slew to the bright alignment star.
> Use the direction buttons to carefully center the alignment star in the eyepiece.
Press ENTER to slew to the desired object.
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COMPUTERIZED TELESCOPE
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.
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.
Observing Tip// 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.
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 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).
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COMPUTERIZED TELESCOPE
UTILITY FEATURES
Scrolling through the MENU options will also provide access to several advanced utility functions
such as anti-backlash compensation and slew limits.
Version - Selecting this option will allow you to see the version number of the Hand Control software.
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.
Get Alt-Az - Displays the relative altitude and azimuth for the current position of the telescope.
Go To Alt-Az - 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:
1. Select “HIBERNATE” from the Utility Menu.
2. Move the telescope to a desire position and press ENTER.
3. 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.
Helpful Hint// 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.
Sun Menu
For safety purposes the Sun will not be displayed as a database object unless it is first enabled.
To enable the Sun, go to the Sun Menu and press ENTER. The Sun will now be displayed in the
Planets catalog and 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.
> 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.
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COMPUTERIZED TELESCOPE
NEXSTAR GT
MENU
ALIGNMENT
LIST
TRACKING
SKYALIGN
NAMED STAR
NAMED OBJECT
ASTERISM
TOUR
VARIABLE STAR
DOUBLE STAR
CCD OBJECT
ABELL
IC CATALOG
CALDWELL
MESSIER
NGC
SAO
SOLAR SYSTEM
CONSTELLATION
MODE
ALT-AZ
EQ NORTH
EQ SOUTH
OFF
SAVED SITE
ENTER IF OK
UNDO TO EDIT
CENTER ALIGNMENT 1
CENTER ALIGNMENT 2
CENTER ALIGNMENT 3
RATE
SIDEREAL
SOLAR
LUNAR
VIEW TIME-SITE
SCOPE SET UP
SETUP TIME-SITE
ANTI-BACKLASH
SLEW LIMITS
SLEW LIMITS
DIRECTION BUTTON
UTILITIES
LIGHT CONTROL
FACTORY SETTING
VERSION
GET ALT-AZ
GOTO ALT-AZ
HIBERNATE
Sun MENU
SCROLLING MENU
AUTO TWO–STAR ALIGN
SAVED SITE
ENTER IF OK
UNDO TO EDIT
SELECT STAR 1
CENTER STAR 1
SELECT STAR 2
CENTER STAR 2
TWO - STAR ALIGNMENT
SAVED SITE
ENTER IF OK
UNDO TO EDIT
SELECT STAR 1
CENTER STAR 1
ONE - STAR ALIGNMENT
SAVED SITE
ENTER IF OK
UNDO TO EDIT
SELECT STAR 1
CENTER STAR 1
USER OBJECTS
GOTO SKY OBJ
SAVE SKY OBJ
SAVE DB OBJ
ENTER RA & DEC
SAVE LAND OBJ
GO TO LAND OBJ
SOLAR SYSTEM ALIGNMENT
SAVED SITE
ENTER IF OK
UNDO TO EDIT
SELECT OBJECT
CENTER OBJECT
GET RA-DEC
GOTO RA-DEC
IDENTIFY
SELECT CATALOG
PRECISE GO TO
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TELESCOPE BASICS
COMPUTERIZED TELESCOPE
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. Your NexStar 102GT telescope is a refractor telescope that uses an
objective lens to collect its 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 NexStar 102GT using the erect image diagonal, the image will
be right side up, and correct from left to right. However, when observing straight through, with the
eyepiece inserted directly into the telescope, the image will be inverted.
CORRECT IMAGE, AS VIEWED
WHEN USING ERECT IMAGE
DIAGONAL
INVERTED IMAGE, AS VIEWED
WITH THE EYEPIECE DIRECTLY IN
TELESCOPE
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:
Focal Length of Telescope (mm)
Magnification =
Focal Length of Eyepiece (mm)
Let’s say, for example, you are using the 25 mm eyepiece. To determine the magnification, you simply
divide the focal length of your telescope (for example, the NexStar 102GT has a focal length of 1000
mm) by the focal length of the eyepiece, 25 mm. Dividing 1000 by 25 yields a magnification of 40
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 102GT is 4.0” (102 mm) in diameter. Multiplying 4.0 by 60 gives a maximum useful magnification of 240 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 80 to 140 times for the NexStar 102GT
telescope.
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COMPUTERIZED 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:
True Field =
Apparent Field of Eyepiece
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 25 mm eyepiece.
The 25 mm eyepiece has an apparent field of view of 40°. Divide the 40° by the magnification, which
is 40 power. This yields an actual field of view of 1.0°.
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 1.0° by 52.5. This produces a
linear field width of 52.5 feet at a distance of one thousand yards.
GENERAL OBSERVING HINTS
When working with any optical instrument, there are a few things to remember to ensure you get the
best possible image:
> 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.
> Never look across or over objects that are producing heat waves. This includes asphalt parking
lots on hot summer days or building rooftops.
> 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.
> 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.
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CELESTIAL OBSERVING
COMPUTERIZED TELESCOPE
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
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
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.
For safe solar viewing, use a safe solar filter to reduce the intensity of the Sun’s light, making it safe to
view. Once you have located and focused the Sun, look for some of the following prominent features:
Sunspots : Dark regions of the Sun’s photosphere which are cooler than the surrounding area.
Sunspots are usually seen to consist of two parts: the inner darker core, the umbra, and the
surrounding less dark region, the penumbra.
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COMPUTERIZED TELESCOPE
Granulation: Small convection cells in the photosphere that appear as “rice grain” markings.
Faculae: Large patches of bright material probably due to elevated clouds of luminous gas
seen in the vicinity of Sunspots.
Limb Darkening: An observed darkening near the limb of the Sun’s surface compared to
its brighter center due to the amount of atmospheric layers penetrated when viewing the Sun’s limb.
Solar Observing Hints
The best time to observe the Sun is in the early morning or late afternoon when the air is cooler.
To center the Sun without looking into the eyepiece, watch the shadow of the telescope tube until it
forms a circular shadow.
To ensure accurate tracking on GT 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.
TERRESTRIAL (LAND) VIEWING
Your NexStar 102GT also makes an excellent daytime spotting scope. For daytime viewing, the 45˚
erect image diagonal must be inserted into the telescope’s focuser. For correct viewing of land objects make sure the eyepiece is pointing straight up out of the diagonal. Rotating the eyepiece and
diagonal to either size will cause the image to also rotate in the field of view of the eyepiece.
TERRESTRIAL (LAND) VIEWING HINTS
To save land objects into your Hand Control’s database as User Defined Objects, first complete
the Quick Alignment procedure, this will bypass the normal two star alignment needed for
nighttime viewing.
Since daytime land objects usually remain stationary, remember to turn off the telescope’s tracking.
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COMPUTERIZED TELESCOPE
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, auroras, natural air glow, and light pollution combined
with transparency can greatly affect viewing conditions. 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.
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 timeto-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.
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TELESCOPE MAITENANCE
COMPUTERIZED TELESCOPE
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 objective lens, you can 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.
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APPENDIX A –
TECHNICAL SPECIFICATIONS
COMPUTERIZED TELESCOPE
OPTICAL SPECIFICATION
ELECTRONIC SPECIFICATIONS
Design
Refractor
Input Voltage
12 V DC Nominal
Aperture
102 mm
Batteries Required
8 AA Alkaline
Focal Length
1000 mm
Power Supply Requirements
12 VDC-750 mA (Tip positive)
F/ratio of the Optical System
F/9.8
MECHANICAL SPECIFICATIONS
Objective Coatings
Fully Coated with Multi Coatings
Motor: Type Resolution
DC Servo motors with encoders, both axes
.26 arc sec,
Highest Useful Magnification
240x
Lowest Useful Magnification
15x
Resolution:
Rayleigh Criterion Dawes Limit
1.37 arc seconds
1.14 arc seconds
Light Gathering Power
212x unaided eye
Field of View: 25 mm Eyepiece
1.0º
Linear Field of View (at 1000 yds)
53 feet
Eyepiece Magnification:
40x (25 mm)
50x (20 mm)
80x (12.5 mm)
125x (8 mm)
250x (4 mm)
Optical Tube Length
35 inches
Slew speeds
Nine slew speeds: 4º /sec, 2º /sec,
1º/sec, .5 /sec, 32x, 16x, 8x, 4x, 2x
Hand Control
Double line, 16 character Liquid Crystal Display
19 fiber optic backlit LED buttons
Fork Arm
Cast aluminum
SOFTWARE SPECIFICATIONS
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
SkyAlign, Auto Two-Star, Two-Star, One-Star,
Solar System Align
Database
25 user defined programmable object.
Enhanced information on over 100 objects
Total Object Database
40,000+ Objects
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GLOSSARY OF TERMS
COMPUTERIZED TELESCOPE
A
Absolute Magnitude
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.
Airy disk
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.
Alt-Azimuth Mounting
A telescope mounting using two independent rotation axes allowing movement of the instrument in
Altitude and Azimuth.
Altitude
In astronomy, the altitude of a celestial object is its Angular Distance above or below the celestial horizon.
Aperture
The diameter of a telescope’s primary lens or mirror; the larger the aperture, the greater the telescope’s
light-gathering power.
Apparent Magnitude
A measure of the relative brightness of a star or other celestial object as perceived by an observer on
Earth.
Arc minute
A unit of angular size equal to 1/60 of a degree.
Arc second
A unit of angular size equal to 1/3,600 of a degree (or 1/60 of an arc minute).
Asterism
A small unofficial grouping of stars in the night sky.
Asteroid
A small, rocky body that orbits a star.
Astrology
The pseudoscientific belief that the positions of stars and planets exert an influence on human affairs;
astrology has nothing in common with astronomy.
Astronomical unit (AU)
The distance between the Earth and the Sun. It is equal to 149,597,900 km., usually rounded off to
150,000,000 km.
Aurora
The emission of light when charged particles from the solar wind slams into and excites atoms and molecules in a planet’s upper atmosphere.
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COMPUTERIZED TELESCOPE
Azimuth
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. .
B
Binary Stars
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.
C
Celestial Equator
The projection of the Earth’s equator on to the celestial sphere. It divides the sky into two equal hemispheres.
Celestial pole
The imaginary projection of Earth’s rotational axis north or south pole onto the celestial sphere.
Celestial Sphere
An imaginary sphere surrounding the Earth, concentric with the Earth’s center.
Collimation
The act of putting a telescope’s optics into perfect alignment.
D
Declination (DEC)
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.
E
Ecliptic
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”.
Equatorial mount
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.
F
Focal length
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.
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COMPUTERIZED TELESCOPE
J
Jovian Planets
Any of the four gas giant planets that are at a greater distance form the Sun than the terrestrial planets.
K
Kuiper Belt
A region beyond the orbit of Neptune extending to about 1000 AU which is a source of many short period comets.
L
Light-Year (ly)
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 1 trillion km (5.87 X 1 trillion mi).
M
Magnitude
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.
Meridian
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.
Messier
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.
N
Nebula
Interstellar cloud of gas and dust. Also refers to any celestial object that has a cloudy appearance.
NORTH CELESTIAL POLE
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”.
Nova
Although Latin for “new” it denotes a star that suddenly becomes explosively bright at the end
of its life cycle.
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COMPUTERIZED TELESCOPE
O
Open Cluster
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.
P
Parallax
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.
Parfocal
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.
Parsec
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 30,8000,000,000,000 km. (Apart from the Sun, no star lies within one
parsec of us.)
Point Source
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.
R
Reflector
A telescope in which the light is collected by means of a mirror.
Resolution
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.
RIGHT ASCENSION (RA): The angular distance of a celestial object measured in hours, minutes, and
seconds along the Celestial Equator eastward from the Vernal Equinox.
S
Sidereal Rate
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.
T
Terminator
The boundary line between the light and dark portion of the Moon or a planet.
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COMPUTERIZED TELESCOPE
U
Universe
The totality of astronomical things, events, relations and energies capable of being described objectively.
V
Variable Star
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.
W
Waning Moon
The period of the Moon’s cycle between full and new, when its illuminated portion is decreasing.
Waxing Moon
The period of the Moon’s cycle between new and full, when its illuminated portion is increasing.
Z
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.
APPENDIX C - RS-232 CONNECTION
For detailed information about controlling NexStar via the RS-232 port, communication protocols and
the RS-232 cable, refer to the NexStar Hand Controls section of the Celestron Knowledge base web
site at: www.celestron.com
APPENDIX D – OTHER RESOURCES
For more information on the use of your new telescope, please be sure to visit the Support pages on
the Celestron website:
www.celestron.com/support
Here you will find set-up videos, the Knowledge base of frequently-asked questions and how to contact Technical Support.
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APPENDIX E – MAPS OF TIME ZONES
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COMPUTERIZED TELESCOPE
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APPENDIX E – MAPS OF TIME ZONES
COMPUTERIZED TELESCOPE
CONTINUED
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COMPUTERIZED TELESCOPE
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COMPUTERIZED TELESCOPE
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COMPUTERIZED TELESCOPE
CELESTRON TWO YEAR WARRANTY
A. Celestron warrants this telescope to be free from defects in materials and workmanship for two years. Celestron will repair
or replace such product or part thereof which, upon inspection by Celestron, is found to be defective in materials or workmanship. As a condition to the obligation of Celestron to repair or replace such product, the product must be returned to Celestron
together with proof-of-purchase satisfactory to Celestron.
B. The Proper Return Authorization Number must be obtained from Celestron in advance of return. Call Celestron at (310) 3289560 to receive the number to be displayed on the outside of your shipping container.
All returns must be accompanied by a written statement setting forth the name, address, and daytime telephone number of the
owner, together with a brief description of any claimed defects. Parts or product for which replacement is made shall become
the property of Celestron.
The customer shall be responsible for all costs of transportation and insurance, both to and from the factory of Celestron, and
shall be required to prepay such costs.
Celestron shall use reasonable efforts to repair or replace any telescope covered by this warranty within thirty days of receipt. In
the event repair or replacement shall require more than thirty days, Celestron shall notify the customer accordingly. Celestron
reserves the right to replace any product which has been discontinued from its product line with a new product of comparable
value and function.
This warranty shall be void and of no force of effect in the event a covered product has been modified in design or function, or
subjected to abuse, misuse, mishandling or unauthorized repair. Further, product malfunction or deterioration due to normal
wear is not covered by this warranty.
CELESTRON DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WHETHER OF MERCHANTABILITY OF FITNESS FOR A
PARTICULAR USE, EXCEPT AS EXPRESSLY SET FORTH HEREIN.
THE SOLE OBLIGATION OF CELESTRON UNDER THIS LIMITED WARRANTY SHALL BE TO REPAIR OR REPLACE THE COVERED PRODUCT, IN ACCORDANCE WITH THE TERMS SET FORTH HEREIN. CELESTRON EXPRESSLY DISCLAIMS ANY
LOST PROFITS, GENERAL, SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES WHICH MAY RESULT FROM BREACH OF
ANY WARRANTY, OR ARISING OUT OF THE USE OR INABILITY TO USE ANY CELESTRON PRODUCT. ANY WARRANTIES
WHICH ARE IMPLIED AND WHICH CANNOT BE DISCLAIMED SHALL BE LIMITED IN DURATION TO A TERM OF TWO YEARS
FROM THE DATE OF ORIGINAL RETAIL PURCHASE.
Some states do not allow the exclusion or limitation of incidental or consequential damages or limitation on how long an implied
warranty lasts, so the above limitations and exclusions may not apply to you.
This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
Celestron reserves the right to modify or discontinue, without prior notice to you, any model or style telescope.
If warranty problems arise, or if you need assistance in using your telescope contact:
CELESTRON
Customer Service Department
2835 Columbia Street | Torrance, CA 90503
TEL (310) 328-9560 | FAX (310) 212-5835
Monday-Friday 8AM-4PM PST
This warranty supersedes all other product warranties.
NOTE: This warranty is valid to U.S.A. and Canadian customers who have purchased this product from an
Authorized Celestron Dealer in the U.S.A. or Canada. Warranty outside the U.S.A. and Canada is valid only
to customers who purchased from a Celestron Distributor or Authorized Celestron Dealer in the specific
country and please contact them for any warranty service.
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COMPUTERIZED TELESCOPE
2835 Columbia Street | Torrance, CA 90503
TEL (310) 328-9560 | FAX (310) 212-5835
www.celestron.com
Copyright 2011 Celestron | All rights reserved.
22093
06-11
Printed in China
$10.00
(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.
Celestron
NexStar 102 GT 102x1000 AZ
Описание
ф мл ни
дит
нл н з 2 мин ты
Д т в
в
м
з
нии
з в
ии
Д т в
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гл
л жб
т чн я
дд ж и
л т
вин и
л т з з любым
д бным
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тзывы
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ид и