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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:
Note: Some of the databases contain thousands of objects, and can therefore take a minute or two to return
the closest object.
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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
If you want to explore the entire object database, set the maximum altitude limit to 90º and the minimum limit to –90º.
Tip!
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
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
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.
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– The direction a star moves in the eyepiece varies depending on the accessories being used.
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