How to Use a Telescope With Setting Circles
- 1). Use setting circles when you know the coordinates of the object. Coordinates can be obtained from star charts and tables of objects in the sky.
- 2). Make sure your telescope is polar aligned before you use the setting circles. (See "How to Polar Align a Telescope" in the Related eHows.)
- 3). Locate a known star that is not too far from the object being sought. The star should be easy to spot and listed in a catalog or star chart.
- 4). Look up the coordinates of the star (or determine them from a star chart). The more accurate the coordinates, the better.
- 5). Move the setting circles to match the values obtained for the star.
- 6). Check the declination setting circle. It should require no correction. If it does, you are not polar aligned or your declination axis has slipped around its holder. Now is a good time to fix it.
- 7). Correct the RA axis. It will most likely require correction unless you are using a permanent observatory or have previously set up for another object.
- 8). Rotate the disk(s) so that the correct values for the object match on your telescope.
- 9). Look up the coordinates of the deep sky object you want to observe.
- 10
Move the telescope so that the coordinates of the telescope match those of the object. If you have done a very precise job of aligning the telescope and setting circles, the object should be in or very near your field of view.
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