Celestron NexStar GT User manual

Celestron International, 2835 Columbia Street, Torrance, CA 90503 • Phone [phone] • Fax [phone]
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. Also included is a Quick-Setup
guide designed to help you quickly assemble and start using your NexStar 60, 80 or 114 telescope. Use
the Quick-Setup guide in conjunction with the complete assembly and operation instruction of the owner's
manual.
Celestron International
Technical Support Dept.
2835 Columbia St.
Torrance, CA 90503
310-328-9560
www.celestron.com

2
2
1
3
.
Fork Arm
Base
Tripod Head
Accessory
Tray
Coupling
Scre
w
A) Remove the NexStar from its packaging. Spread the
tripod legs apart until the center leg brace is fully
extended and attach the accessory tray. B) Extend the
tripod legs to the desired height. C) Set the telescope fork
arm base into the tripod head and thread the coupling
screw into the bottom of the base.
4
Hand
Control
Outlet
Battery
Pack
Outlet
Install 8 AA batteries into the battery pack. Plug in
the hand control and the battery pack into the
outlets on the fork arm base.
The first time the NexStar is powered on the display will
read Select Model. Use the Up and Down scroll buttons to
select your NexStar model from the list and press ENTER.
When the display reads NexStar Ready, press ENTER to
AutoAlign the NexStar. The hand control display will ask
you to move the telescope tube so that it is level with the
ground and facing the north horizon. Use the direction
arrow buttons on the hand control to position the telescope
north and level. (See Astronomy Basics forhelponfinding
north).
A) Attach the included accessories. Loosen the thumb screw at the
end of the focuser and remove the protective plastic cap. Insert the
diagonal (60mm and 80mm models only) and low power eyepiece
(25mm or 20mm) into the barrel of the focuser. B) Remove the
front lens cover from the end of the telescope. C) Attach the Star
Pointer finderscope and remove the plastic cover over the battery
and turn-on the Star Pointer by rotating the dial on the side. (For
instructions on aligning the Star Pointer, see the Assembly section o
f
the manual).
Eyepiece Star Pointer
Focus Knob
Star Diagonal

3
TOUR Button
Object Lis
t
Butto
n
Catalog Keys
7
5
6
Use the Up and Down scroll buttons and choose from
the city database the closest city to your present
location. Then input the necessary date and time
information as instructed by the hand control. Press
ENTER after each entry. (See Hand Control section
of the manual for detailed alignment procedures).
Alignment Star
StarPointer Finderscope
The NexStar will automatically choose an alignment star and slew
the telescope close to that star. Once there, the display will as
k
you to use the arrow buttons to aim the Star Pointer at the star. I
f
the star is not visible (perhaps behind a tree), press UNDO to
select a new star. Next, focus and center the star in the eyepiece
and press ALIGN. Repeat these steps for the second star
alignment. When complete, the display will read "Alignment
AlignmentAlignment
Alignment
Successful"
Successful"Successful"
Successful".
Press the TOUR button on the hand control. The hand control
will display a list of objects that are visible for the date and
location entered. Press INFO to read information about the
object displayed. Press the DOWN scroll key to display the
next object. Press ENTER to slew to (go to) the displayed
object.
Up and Down
Scroll Buttons
Direction
Buttons

4
A
At tt ta ac ch hi in ng gt th he eH Ha an nd dC Co on nt tr ro ol l
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.
P
Po ow we er ri in ng gt th he eN Ne ex xS St ta ar r
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 hand control will display the message NexStar Ready
NexStar ReadyNexStar Ready
NexStar Ready.
In case of a loss of power, the optical tube can be moved by hand. However, when powered on, the telescope should always
be controlled via the hand control. The NexStar will lose its star alignment if moved by hand when powered on.
T
Th he eH Ha an nd dC Co on nt tr ro ol l
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.
4. Catalog Keys: The NexStar has a separate 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:
Note
Figure 3-1 – The NexStar GT Outlets
Hand Control
Outle
t
Battery Pack
Outlet
Battery Pack

5
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 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.
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.
1
2
3
4
5
6
7
8
11
12
9
10
Figu ur re e3 3- -2 2
The NexStar GT Hand Control

6
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.
H
Ha an nd dC Co on nt tr ro ol lO Op pe er ra at ti io on n
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.
A
Al li ig gn nm me en nt tP Pr ro oc ce ed du ur re e
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.
A
Au ut to o- -A Al li ig gn n
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.
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 ModelSelect Model
Select Model. Use the Up and Down menu keys (10) to 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 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.

7
 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
United StatesUnited States
United States is displayed. For international locations,
use the Up or Down scroll key to select International
InternationalInternational
International and press ENTER.
 To display a list of local cities, first select your state from the alphabetical listing (or a list of countries if
International locations was selected) and press ENTER.
 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 Up and Down scroll buttons (10) to toggle
between options.
 Select the time zone that you are observing from. Again, use the Up and Down buttons (10) to scroll through the
choices. For time zone information, refer to the Time Zone map in the appendix of this manual.
Date - Enter the month, day and year of your observing session. The display will read: mm/dd/yy.
• 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 Auto Aligned, the hand control will automatically display the last location
(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 the Star
Pointer finder. Once finished slewing, the display will ask you to use the arrow buttons to align the selected star with the red
dot in the center of the Star Pointer. If for some reason the chosen star is not visible (perhaps behind a tree or building) you
can press UNDO to select and slew to a different star. 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 first alignment star. (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 Star Pointer and the eyepiece). After the first
alignment star has been entered the NexStar will automatically slew to a second alignment star and have you repeat the same
procedure for that star. When the telescope has been aligned to both stars the display will read Alignment Successful
Alignment SuccessfulAlignment Successful
Alignment Successful,
and you are now ready to find your first object.
If the wrong star was centered and aligned to, the NexStar display will read Align Failed
Align FailedAlign Failed
Align Failed.Press UNDO to begin the
alignment procedure again.
If you are not sure if the correct star was centered, always remember that the alignment star will be the brightest
star nearest the field of view of the finder. There may be other fainter stars visible that are closer to the center of the
Star Pointer, but the actual alignment star will be obviously brighter than any other star in the area.
When centeringthealignmentstars intheeyepiece oftheNexStar 60/80, usethe down arrow buttonandthe right
arrow button on the hand control. Centering the star from this direction will eliminate much of the backlash between
thegears andassure themost accurate alignmentpossible. With the NexStar 114,centerthe star using the up arrow
button and the right arrow button on the hand control.
T
Tw wo oS St ta ar rA Al li ig gn nm me en nt t
With the two-star alignment method, the NexStar requires the user to know the positions of only 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:
Helpful
Hints
O
bserving
T
Ti ip ps s

8
1. Once the NexStar is powered on, use the Up and Down scroll keys to select Two
TwoTwo
Two-
--
-Star Align
Star AlignStar Align
Star Align,and press
ENTER.
2. The NexStar display will ask you to move the telescope tube until it is horizontal to the ground. To do this, use
the direction keys (3) to move the telescope until it is roughly level with the ground. Press ENTER.
3. The SELECT STAR 1
SELECT STAR 1SELECT STAR 1
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 buttons to slew
the telescope to the alignment star and carefully center the star in the eyepiece.
5. Once the alignment star is centered in the field of view of the eyepiece, press the ALIGN key (2) to accept this
position.
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 Alignment Successf
Alignment SuccessfAlignment Successf
Alignment Successful
ulul
ul, and you will hear the
tracking motors turn-on and begin to track.
Q
Qu ui ic ck k- -A Al li ig gn n
Quick-Align allows you to input all the same information as you would for the AutoAlign procedure. However, instead of
slewing to two alignment stars for centering and alignment, the NexStar bypasses this step and simply models 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 while in altazimuth mode. Quick-Align is not meant to be used
to accurately locate small or faint deep-sky objects or to track objects accurately for photography. Note: Once a Quick-Align
has been done, you can use the Re-alignment feature (see below) to improve your telescopes pointing and tracking accuracy.
To use Quick-Align:
1. Select Quick-Align from the alignment options.
2. Use the arrow buttons to level the tube and position the telescope tube towards north and press ENTER.
3. The hand control will then ask you to input all the same time and location information as you would for the
AutoAlign procedure.
Once entered, the NexStar will model the sky based on this information and display Alignment Successful
Alignment SuccessfulAlignment Successful
Alignment Successful.
N
Ne ex xS St ta ar rR Re e- -A Al li ig gn nm me en nt t
The NexStar has a re-alignment feature which allows you to replace either of the two 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 Quick-Align method, you can use re-align to align to two actual
objects 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 Ready 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.
7. Press ALIGN to make the change.

9
O
Ob bj je ec ct tC Ca at ta al lo og g
S
Se el le ec ct ti in ng ga an nO Ob bj je ec ct t
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 (10) 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.
To download a list of all the stars contained in the STAR Catalog with SAO number cross references, logon to our web site
at www.celestron.com.
S
Sl le ew wi in ng gt to oa an nO Ob bj je ec ct t
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.
The speed at which information scrolls across the hand control display can be changed while the information is being
viewed:
Press the “1” key repeatedly to speed up the scroll speed.
Press the “4” key repeatedly to slow down the scroll speed.
Press the “7” key to freeze and unfreeze the information on the display.
•
••
• 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 Utility Features 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. If you wish to stop the telescope from slewing, press any of the
direction buttons on the hand control.
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.
T
To ou ur rM Mo od de e
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

10
filter limits. To activate the Tour mode, press the TOUR key (6) 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.
D
Di ir re ec ct ti io on nB Bu ut tt to on ns s
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
R
Ra at te eB Bu ut tt to on n
Pressing the RATE key (11) allows you to instantly change the speed rate of the motors from high speed slew rate to precise
guiding rate or anywhere in between. Each rate corresponds to a number on the hand controller key pad. The number 9 is
the fastest rate (approximately 4º per second, depending on power source) and is used for slewing between objects and
locating alignment stars. The number 1 on the hand control is the slowest rate (2x sidereal) and can be used for accurate
centering of objects in the eyepiece. To change the speed rate of the motors:
•
••
• Press the RATE key on the hand control. The LCD will display the current speed rate.
•
••
• Press the number on the hand control that corresponds to the desired speed.
The hand control has a "double button" feature that allows you to instantly speed up the motors without having to choose a
speed rate. To use this feature, simply press the arrow button that corresponds to the direction that you want to move the
telescope. While holding that button down, press the opposite directional button. This will increase the speed to the
maximum slew rate.
When using the Up and Down buttons on the NexStar 60 and 80, the slower slew rates (6 and lower) move the motors in the
opposite direction than the faster slew rates (7- 9). This is done so that an object will move in the appropriate direction
when looking into the eyepiece (i.e. pressing the up arrow button will move the star upwards in the field of view of the
eyepiece). However, if any of the slower slew rates (rate 6 and below) are used to center an object in the Star Pointer, you
may need to press the opposite directional button to make the telescope move in the correct direction.
S
Se et tU Up pP Pr ro oc ce ed du ur re es s
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.
Nine available slew speeds

11
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, such as the
NexStar 4, 5 and 8. The NexStar 60, 80 and 114 are exclusively Alt-Az mounted telescopes and do not require
equatorial tracking.
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.
Sidereal Time –Displays the Sidereal time for your current time and location. This is useful for knowing the right
ascension of celestial objects that are located on the local meridian at that time.
Filter Limits – When an alignment is complete, the NexStar automatically knows which celestial objects are above the
horizon. As a result, when scrolling through the database lists (or selecting the Tour function), the NexStar hand control
will display only those objects that are known to be above the horizon when you are observing. You can customize the
object database by selecting altitude limits that are appropriate for your location and situation. For example, if you are
observing from a mountainous location where the horizon is partially obscured, you can set your minimum altitude limit to
read +20º. This will make sure that the hand control only displays objects that are higher in altitude than 20º.
If you want to explore the entire object database, set the maximum altitude limit to 90º and the minimum limit to –90º. This
will display every object in the database lists regardless of whether it is visible in the sky from your location or not.
RS-232 - The NexStar has a RS-232 port located on the bottom of the hand control that allows it to communicate with
many astronomy computer programs such as enhanced versions of The Sky® by Software Bisque. Before attempting to
create a link with a computer , select the RS-232 option and press Enter.
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
Save SkySave Sky
Save Sky
Obj"
Obj"Obj"
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: 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
Observing
Tip!

12
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
Save Land ObjSave Land Obj
Save Land Obj" command and press
ENTER. The display will ask you to enter a number between 1-25 to identify the object.
Press ENTER again to save this object to the database.
Enter R.A. - Dec: You can also store a specific set of coordinates for an object just by entering the R.A. and
declination for that object. Scroll to the "Enter RA
Enter RAEnter RA
Enter RA-
--
-DEC "
DEC "DEC "
DEC " command and press ENTER.
The display will then ask you to enter first the R.A. and then the declination of the desired
object.
GoTo Object: To go to any of the user defined objects stored in the database, scroll down to either GoTo
GoToGoTo
GoTo
Sky Obj
Sky ObjSky Obj
Sky Obj or Goto
GotoGoto
Goto Land Obj
Land ObjLand Obj
Land Obj and enter the number of the object you wish to select and
press ENTER. NexStar will automatically retrieve and display the coordinates before
slewing to the object.
To replace the contents of any of the user defined objects, simply save a new object using one of the existing identification
numbers; NexStar will replace the previous user defined object with the current one.
Get RA-DEC - Displays the right ascension and declination for the current position of the telescope.
Get Alt-Az - Displays the relative altitude and azimuth for the current position of the telescope.
Goto R.A-Dec - Allows you to input a specific R.A. and declination and slew to it.
Goto Alt-Az - Allows you to enter a specific altitude and azimuth position and slew to it.
To store a set of coordinates (R.A./Dec) permanently into the NexStar database, save it as a User Defined Object as
described above.
U
Ut ti il li it ty yF Fe ea at tu ur re es s
Scrolling through the MENU options will also provide access to several advanced utility
functions such as anti-backlash compensation and slew limits.
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. Anti-backlash has both a positive and negative value that can be
changed. The positive setting will quickly rewind the motor backwards once a button has
been released that is moving the telescope in the same direction that the telescope is
tracking. The negative setting will immediately speed up the motors whenever the
opposite direction button has been pressed. This will eliminate much of the backlash
created when reversing the direction of the motors. 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.
Helpful
Hint
SETUP TIME-SITE
A Z M P O S IT IV E
AZM NEGATIVE
A L T P O S IT IV E
ALT NEGATIVE
ANTI-BACKLASH
SLEW ALT MAX
SLEW ALT MIN
SLEW LIMITS
AZM BUTTONS
ALT BUTTONS
DIRECTION BUTTONS
DISPLAY OFF
DISPLAY ON
KEY PAD OFF
KEY PAD ON
LIGHT CONTROL
SELECT M ODEL
UT ILITIES
MENU

13
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.
Direction Buttons –The direction a star moves in the eyepiece varies depending on the accessories being used. This
can create confusion when guiding on a star using an off-axis guider versus a straight through guide scope. To compensate
for this, the direction of the drive control keys can be changed. To reverse the button logic of the hand control, press the
MENU button and select Direction Buttons from the Utilities menu. Use the Up/Down arrow keys (10) to select either the
Azimuth buttons (left and right) or Altitude buttons (up and down) and press ENTER. Pressing ENTER again will reverse
the direction of the hand control buttons from their current state. Direction Buttons will only change the eyepiece rates (rate
1-6) and will not affect the slew rates (rate 7-9).
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.
Select Model – The first time the NexStar is powered on, the hand control display allows you to select your NexStar
from a list of different models. 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. Once the correct NexStar model has been selected the power needs to be restarted before beginning the
alignment procedure. The Select Model feature will return the hand control to its original factory settings. Parameters such
as backlash compensation values along with slew and filter limits will be reset. However, stored parameters such as user
defined objects will remain saved even after the model has been changed.

14
ALT-AZ
EQ NORTH
EQ SOUTH
OFF
MODE
SIDEREAL
SOLAR
LUNAR
RATE
TRACKING
VIEW TIM E-SITE
SIDEREAL TIM E
ALTMAX IN LIST
A L T M IN IN L IS T
FILTER LIM ITS
SETUP TIME/SITE
ANTI-BACKLASH
SLEW LIMITS
DIRECTION BUTTONS
LIGHT CONTROL
SELECT MODEL
UTILIT IES
RS-232
GOTO SKY OBJ
SAVE SKY OBJ
ENTER RA & DEC
GOTO LAND OBJ
SAVE LAND OBJ
USER OBJECTS
GET ALT-AZ
GOTO ALT-AZ
GET RA-DEC
GOTO RA-DEC
MENU
Enter Date
Enter Time
Choose City
Choose State
United States
Choose City
Choose Country
Intern ation al
CITY DATABASE
Enter Time
Enter Date
Enter Long/Lat
CUSTOM SITE
POINT TUBE NORTH & LEVEL
AUTO ALIGN
CENTER STAR 1
SELECT STAR 1
CENTER STAR 2
SELECT STAR 2
LEVEL TUBE
TWO-STAR ALIGNMENT
SELECT LOCATION
ENTER TIME
ENTER DATE
POINT TUBE NORTH & LEVEL
QUICK ALIGN
ALIGNMENT
NAMED STAR
NAMED OBJECT
ASTERISMS
TOUR
VARIABLE STAR
DOUBLE STAR
CALDW ELL
MESSIER
NGC
SOLAR SYSTEM
SAO
LIST
NexStar Ready
NexStar Menu Tree:
The following figure is a menu tree showing the sub-menus associated with the primary command
functions

15
APPENDIX C – MAPS OF TIME ZONES

16