Searches for Optical Counterparts of BATSE Gamma-ray Bursts with the Explosive Transient Camera

Hans A. Krimm, Roland K. Vanderspek and George R. Ricker

Department of Physics and Astronomy, Hampden-Sydney College
Hampden-Sydney, VA 23943 U.S.A.
Center for Space Research and Department of Physics
Massachusetts Institute of Technology
Cambridge, MA 02139 U.S.A.

Abstract:

The Explosive Transient Camera (ETC) is a wide-field CCD camera system capable of detecting short (1-10 s) celestial optical flashes as faint as m ~10 over a field-of-view of 0.75 steradians between -15 and +62 degrees declination. The ETC has been operating automatically under computer control since January 1991. Since the launch of the Compton Gamma Ray Observatory, the ETC has been capable of observing an optical flash coincident with a gamma-ray burst (GRB) detected by the Burst and Transient Source Experiment (BATSE). Between April 1991 and August 1995, there were seven cases of at least partial spatial overlap between a BATSE 68% confidence positional error box and the ETC field-of-view during an ETC observation. In each case upper limits are placed on the optical-to-gamma-ray flux ratio.

Hans Krimm
Thu Jun 13 14:06:17 EDT 1996