Stellarium

[Craigx]

Hi,

just downloaded the Stellarium program - brilliant. However, I am confused about one item at the moment. The data panel in the top left hand screen for identified objects shows two RA/DE lines - one for (j2000) and the other for (of date). Which do I use to find things in the sky. Please be gentle I am new to all this!

[Daggerstab]

You may be familiar with the equatorial coordinate system. If not:

Celestial coordinate system - Wikipedia, the free encyclopedia

Equatorial coordinate system - Wikipedia, the free encyclopedia

J2000 and "of date" refer to the fact that due to precession, coordinates fixed at some date won't be necessary valid for another date years later. "J2000" means that these are the coordinates for Julian epoch 2000.0. "of date" means that the coordinates have been corrected for precession.

If you don't have a telescope with setting circles, a much more useful pair of coordinates in Stellarium would be the "Azimuth/Altitude" pair. It shows the compass bearing to the object in the given moment and how high in the sky it is.

[Craigx]

Thank you - just what I needed.

[Astrosurf]

Great for me too!

Alexxx