TITLE: GCN CIRCULAR NUMBER: 6841 SUBJECT: GRB 071003: MARGE Observations DATE: 07/10/03 22:02:30 GMT FROM: Heather Swan at U.of Michigan/ROTSE H. Swan (U Mich), I. Smith (Rice), W. Rujopakarn (Steward), F. Yuan (U Mich), S. Yost (College of St. Benedict), C. Akerlof (U Mich), M. Skinner (Boeing), R. Russell (Aerospace Corporation) report on behalf of the MARGE collaboration: The AEOS Burst Camera (ABC) on the AEOS telescope, located at the Maui Space Surveillance System on Haleakala, observed the fading counterpart to GRB071003 (Swift trigger 292934 (P. Schady et al. GCN 6837)). The images are unfiltered 10s exposures which started ~9 minutes after the trigger and ended ~ 3 hours later. We detect the OT first identified by W. Li (GCN 6838). A preliminary analysis gives a magnitude of approximately 16.04+/-0.01 at 7:40:55 UT. We calibrated the OT to the USNO-B1.0 R2 band magnitudes of several nearby stars. We find that the early ABC data fades as a power law decay with index ~1.9. We note that the lightcurve has a flatter decay index after about 2000 seconds. This may be partially due to contamination from the nearby 10.79 mag star that will be resolved by more careful analysis. It is possible that the OT is still visible (< 22nd mag). Further observations are planned.