Guide Users,
On the evening of 2001 April 26/27, a fellow member of the Amateur
Astronomers Association of Pittsburgh, John Holtz, and I observed the
NEA 2001 GQ2, using tracking charts prepared by use of Guide 7.0. We
used the 20-inch Manka reflector at the AAAP's Wagman Observatory in the
northeast corner of Allegheny Observatory, near Pittsburgh. The sky was
clear and the Moon had set.
Orbital elements were obtained by telenet from the Center for
Astrophysics and Planetary Science and entered into Guide. Without
topocentric adjustment the positions computed by Guide were exactly the
same as in the geocentric ephemeris computed by CFAPS. For Guide, the
observatory's location was entered (79.81 deg W, 40.63 deg N, altitude
400 m), and topcentric positions were computed. Tracks were generated
for the first few hours UT of April 25, 26, 27, 28, which include the
evening hours EST of April 24, 25, 26, and 27, and the charts were
printed by Guide on a LaserJet printer. For our search we used Level 6
(5 deg) charts with limiting star magnitude set at 15.0, since the
asteroid was predicted to be around magnitude 14.2 that night. After
considerable searching, John spotted the moving object around 11:30 PM,
and about three times in the next half-hour we could see it by averted
vision as it passed some stars. It was exactly on the plotted track.
I have used tracking charts prepared with Guide for observing a
number of other asteroids. It's a fantastic program!
Truman

Truman P. Kohman, Departments Chemistry and Physics
Carnegie-Mellon University, Pittsburgh, PA 15213 USA
Phone: 412/268-8865, 412/561-8343 Fax: 412/681-0648
Internet - ASCII messages and documents: tk11+@...
For images and coded attachments: tpkohman@...