Celestron NexStar GT User Manual

Addendum For NexStar GT Hand Control Section Of The Owner's Manual.

The following is an addendum to the NexStar GT section of the owner's manual that explains the current
operation and added features to your NexStar hand control. Please refer to these pages for specific
information regarding telescope alignment and hand control functions.

Celestron International

Technical Support Dept.
2835 Columbia St.
Torrance, CA 90503
310-328-9560
www.celestron.com

Celestron International, 2835 Columbia Street, Torrance, CA 90503 • Phone [phone] • Fax [phone]

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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 4,000 objects, and common sense menu descriptions, even a beginner can master its
variety of features in just a few observing sessions. Below is a brief description of the individual components of the
NexStar 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.

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The NexStar GT Hand Control

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4. Catalog Keys: The NexStar has a key on the hand control to allow direct access to each of the catalogs in its

4,000+ object database. The NexStar contains the following catalogs in its database:

Messier – Complete list of all Messier objects.
NGC – Many of the brightest deep sky objects from the Revised New General Catalog.
Caldwell – A combination of the best NGC and IC objects.
Planets - All 8 planets in our Solar System plus the Moon.
Stars – A compiled list of the brightest stars from the SAO catalog.
List – For quick access, all of the best and most popular objects in the NexStar database have been

broken down into lists based on their type and/or common name:

Named Stars
Named Objects

Double Stars

Variable Stars

Asterisms

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 point and click slewing capability.

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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.

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Common name listing of the brightest stars in the sky.
Alphabetical listing of over 50 of the most popular deep
sky objects.
Alphabetical listing of the most visually stunning double,
triple and quadruple stars in the sky.
Select list of the brightest variable stars with the shortest
period of changing magnitude.
A unique list of some of the most recognizable star
patterns in the sky.

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In order for the NexStar to accurately point to objects in the sky, it must first be aligned with two 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.

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Auto-Align is the easiest way to get your NexStar aligned and ready to observe. Even if you do not know a single star
in the sky, the NexStar will align itself by guiding the user through the alignment procedure by asking for basic
information like the date, time and location. The NexStar will then automatically choose two stars for alignment and
roughly center the stars in the field of view of the Star Pointer. Before the telescope is ready to be aligned, it should be
set up in an outside location with all accessories (eyepiece, diagonal and Star Pointer) attached and lens cover removed
as described in the Assembly section of the manual.

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1. Once the NexStar is powered on the display will read NexStar Ready.Press ENTER to begin alignment.

The first time that the NexStar is used, it will request information to help identify the model of telescope. Once
powered on, the hand control will display the message Select Model

Select Model. Use the Up and Down menu keys (10) to

Select ModelSelect Model

scroll through the different NexStar models. Press ENTER when your NexStar model is displayed on the hand control.
This information will be retained for future use and will not be displayed again. If for some reason the incorrect model
was selected or you wish to use your hand control on a different NexStar model, the Select Model utility feature allows
you to re-select the proper NexStar model from the displayed list (see Select Model later in this section).

2. Use the Up and Down scroll keys to select AutoAlign if it is not already displayed, and press ENTER.

3. The telescope will then ask you to use the direction keys (3) to level the telescope tube and point the front of the
telescope towards north. North can be found by finding the direction of the North Star (Polaris) or by using a
compass. You do not need to point at the North Star, only the north horizon. Alignment only needs to be
approximate, however a close alignment will make the auto alignment more accurate. Once the telescope is in the
north and level position, press ENTER.

4. The hand control display will then ask for the following information:

Location - The NexStar will display a list of cities to choose from. Choose the city from the database that is

closest to your current observing site. The city you choose will be remembered in the hand controls
memory so that it will be automatically displayed the next time an alignment is done. Alternatively, if
you know the exact longitude and latitude of your observing site, it can be entered directly into the
hand control and remembered for future use as well. To choose a location city:

Use the Up and Down scroll keys to choose between City Database and Custom Site. City Database will

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allow you to select the closest city to your observing site from a list of either international or U.S. location.
Custom Site allows you to enter the exact longitude and latitude of your observing site. Select City Database
and press ENTER.

The hand control will allow you to choose from either U.S. or international locations. For a listing of U.S.

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locations by state and then by city, press ENTER while United States
locations, use the Up or Down scroll key to select International

International and press ENTER.

InternationalInternational

United States is displayed. For international

United StatesUnited States

Helpful

Hints

To display a list of local cities, first select your state from the alphabetical listing (or a list of countries if

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International locations was selected) and press ENTER.

Choose the closest city to your location from the displayed list and press ENTER.

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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.

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Choose between Standard time or Daylight Savings time. Use the Up and Down scroll buttons (10) to toggle

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between options.

Select the time zone that you are observing from. Again, use the Up and Down buttons (10) to scroll through

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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

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allowing the user to re-enter information.

The next time that your NexStar is Auto Aligned, the hand control will automatically display the last location

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(either a city or longitude/latitude) that was entered. Pressing the UNDO button will allow you to go back
and select a new city location or longitude/latitude.

Based on this information, the NexStar will automatically select a bright star that is above the horizon and slew towards
it. At this point the telescope is only roughly aligned, so the alignment star should only be close to the field of view of

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