Dec. coordinate indicator arrow
Celestial equator (Dec. = 0°)
Use these numbers on the R.A. setting circle (Northern Hemisphere)
Plastic R.A. gear cover
R.A. coordinate indicator arrow
Figure 7. For Northern Hemisphere observers, use the lower set of numbers on the R.A. setting circle. The R.A. coordinate indicator arrow is between the “R” and the “A” on the plastic gear cover. The telescope (not shown) is pointing north of the celestial equator, so the approximate coordinates of the mount in the image are R.A. 8h 30m Dec. 60°.
Finding Objects With the Setting Circles
Now that both setting circles are calibrated, look up in a star atlas the coordinates of an object you wish to view.
1.Loosen the Dec. lock knob and rotate the telescope until the Dec. value from the star atlas matches the reading on the Dec. setting circle. Remember that values of the Dec. setting circle are positive when the telescope is pointing north of the celestial equator (Dec. = 0°), and negative when the telescope is pointing south of the celestial equa- tor. Retighten the lock knob.
2.Loosen the R.A. lock knob and rotate the telescope until the R.A. value from the star atlas matches the reading on the R.A. setting circle. Remember to use the lower set of numbers on the R.A. setting circle. Retighten the lock knob.
Most setting circles are not accurate enough to put an object
object in the finder scope, and it should appear in the tele- scope’s field of view.
The R.A. setting circle must be
Confused About Pointing the Telescope?
Beginners occasionally experience some confusion about how to point the telescope overhead or in other directions. In Figure 1 the telescope is pointed north, as it would be during polar alignment. The counterweight shaft is oriented downward. But it will not look like that when the telescope is pointed in other directions. Let’s say you want to view an object that is directly overhead, at the zenith. How do you do it?
DO NOT make any adjustment to the latitude adjustment t- bolt. That will nullify the mount’s polar alignment. Remember, once the mount is polar aligned, the telescope should be moved only on the R.A. and Dec. axes. To point the scope overhead, first loosen the R.A. lock knob and rotate the tele- scope on the R.A. axis until the counterweight shaft is horizontal (parallel to the ground). Then loosen the Dec. lock knob and rotate the telescope until it is pointing straight over- head. The counterweight shaft is still horizontal. Then retighten both lock knobs.
Similarly, to point the telescope directly south, the counter- weight shaft should again be horizontal. Then you simply rotate the scope on the Dec. axis until it points in the south direction.
What if you need to aim the telescope directly north, but at an object that is nearer to the horizon than Polaris? You can’t do it with the counterweight down as pictured in Figure 1. Again, you have to rotate the scope in R.A. so the counterweight shaft is positioned horizontally. Then rotate the scope in Dec. so it points to where you want it near the horizon.
To point the telescope to the east or west, or in other direc- tions, rotate the telescope on its R.A. and Dec. axes. Depending on the altitude of the object you want to observe, the counterweight shaft will be oriented somewhere between vertical and horizontal.
Figure 8 illustrates how the telescope will look pointed at the four cardinal
The key things to remember when pointing the telescope is that a) you only move it in R.A. and Dec., not in azimuth or lat- itude (altitude), and b) in actual use the counterweight and shaft will rarely appear as it does in Figure 1.
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