Celestron NexStar GT User Manual
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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:
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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.
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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, 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
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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.