Hi folks,

About rise/set/transit times: these are computed as described by
Paul Schlyter, and follow "standard" definitions for each. I don't
think you'll find any program that uses a different definition of "rise",
"set", or "twilight".

Regarding creating your own, specific horizon: there are a couple
of things you can do here. By default, when you go into "Display...
Backgrounds" and turn the ground and horizon objects on, Guide shows
a horizon at zero degrees altitude and with assorted objects (trees,
cars, houses, telescopes, etc.) strewn around the horizon. You can
edit these objects by following directions at the bottom of the file
HORIZON.DAT, in the Guide directory. Setting up an horizon as a series
of alt/az points is discussed at the end of HORIZO10.DAT (horizon data
for the Moon), and/or at

http://www.projectpluto.com/update7c.htm#easier_horizon

There was an article in _Sky & Telescope_ a while back about how
rise/set times vary with atmospheric conditions, in some cases so much
that the sun will appear to rise briefly above the horizon, drop back
down, then finally rise "for real". Unfortunately, I don't remember
which issue that was.

Truman, about the "banner" at the top of the application, which
usually reads "Guide 7": you've got a good point here. This is really a
large chunk of poorly-used screen space, which (as you suggested) could
tell you the last mark file loaded, or (more generally) the last object
"gone to" or clicked on, or the RA/dec/constellation of the screen center,
or the field of view, and so on. Having it tell you the name of the
program is not, when you come down to it, really all that helpful.

-- Bill