Quote:
Originally Posted by Menthu Rae
... What I don't understand are the dials (marked 0-23 on the RA axis and every 10 degrees on the DE axis) on both axes. Especially the fact that the RA axis dial can be moved around...
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You point the scope at an object with known RA and then rotate the dial so the index mark matches the RA of the object. As long as you don't physically move the mount, the dial will rotate with the RA axis and stay correct.
Quote:
... I understand that objects can be pinpointed by RA/DE - but I also don't understand in stellarium what the different references are... you have
- RA/DE (J2000)
- RA/DE (of date)
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RA changes over time for reasons related to the earths orbit and polar inclination. While you are getting started the difference between J2000 and other recent epochs is hardly worth worrying about.
Getting your GEM aligned both quickly and accurately is not something you learn overnight. Go along to a viewing night and the old hands will be happy to show you the tricks of the trade.