Davoud wrote in message ...
[...]
I'm not very good at spherical geometry, so please bear with me here. I
don't want to go to the expense of controlling the dome's rotation by
computer, but I would like to auto-rotate it. Would it work to simply
install a motorized rotator that would rotate the dome at 15° per hour?
I figure that when I want to move the telescope to a new target I could
disengage the rotator and manually rotate the dome to a new starting
position, the re-engage. So, will that work?

Nope. (Not unless you tilt the dome and polar-align it :-)

Seriously, a quick way to check this for yourself is to use any sky chart
or planetarium program, pick an object (such as a star), step the time hour
by hour and note the azimuth reported by the program for that object.

Think about it for moment. Suppose you wanted to view/image Polaris for,
say, 5 hours. Chances are you wouldn't need to rotate the dome at all.
Unless you want to rotate the dome manually, you'll need a "smart" interface.

One possibility to do it on a budget would be the "Talon" program featured in
the January 2004 issue of LINUX JOURNAL. The article can also be found online
at URL:

http://www.linuxjournal.com/article.php?sid=6673

FWIW, Talon incorporates XEphem as one of its components. Contrary to the
article, the source code is found in the CVS section at:

http://sourceforge.net/projects/observatory/