CCD Astrometry of Near—Earth Asteroids

Extract

Automated observations of near-Earth asteroids have been underway at the USNO Flagstaff Station since February 1994. Observations are made with an 8-inch transit telescope utilizing a CRAF/Cassini 1024×1024 CCD. The scale of 1.2 arcsec/pixel provides a field 20.5 arcmin on a side. Pointing and imaging are done automatically using nightly schedules of transit times and declinations of the asteroids to be observed. Observations are made in scan mode, allowing an integration time of 80 seconds at the celestial equator and a limiting magnitude of about 17.5. Flats, collimation and scale frames, and photometric standard fields can all be included in the nightly schedules. The telescope operates unattended during the night, but is monitored remotely by observers at another USNO telescope.