Use of a scanning CCD to discriminate asteroid images moving in a field of stars.

The authors are using a charge-coupled device (CCD) in a scanning mode to find new asteroids and recover known asteroids and comet nuclei. The routine "six sigma" limiting visual magnitude is 19.6 and slightly more than a square degree is scanned three times every 90 minutes of observing time during the fortnight centered on new moon. Semiautomatic software for detection of moving objects is in routine use; angular speeds as low as 11.0 arcseconds per hour have been distinguished from the effects of the Earth's atmosphere on the field of view. In 18 observing runs (months) the authors have recovered 43 asteroids, discovered and reported astrometric and photometric data on 59 new asteroids, consolidated 10 new asteroids with orbital elements, and reported photometry and positions of 22 comets.