At 02:27 PM 1/9/2003 -0600, you wrote:

>Recently someone referred to the USNO B.1. I assume
>this is an improvement on the USNO A.2. Is there a
>website where I can learn more about this?

The main difference IMO is source density (one billion objects down to
V=21) and the inclusion of proper motions. Like A2, magnitudes are not to
be trusted.

The gory details can be found at:

http://xxx.lanl.gov/abs/astro-ph/0210694


--
Jeff Medkeff
Sierra Vista, Arizona
http://www.roboticobservatory.com/jeff/