GCN Circular 2384
Magellan Observations of GRB030725 (=H2779) A. Dullighan, N. Butler, R. Vanderspek, J. Villasenor, and G. Ricker (MIT) write: We have observed the optical counterpart (Monard, GCN 2324) of the HETE-discovered Gamma Ray Burst GRB030725(=H2779; Shirasaki et al, GCN 2322) with the MagIC instrument on the 6.5m Magellan Clay telescope at Las Campanas Observatory in Chile. Two 300 second, Sloan r-band exposures were taken in an interval centered on August 1.305 UT, at 6.81 days after the burst. Another two 360 sec Sloan r-band exposures were taken on August 2.166 UT, at 7.68 days after the burst. Date UT r Magnitude August 1.305 22.25 +/- 0.05 August 2.166 22.55 +/- 0.05 These measurements are consistent with the late time decay slope of -1.4 +/- 0.1 as reported by Jorgensen, et al. (GCN 2344). A lightcurve for the optical afterglow of GRB 030725 can be seen at: http://space.mit.edu/HETE/Bursts/GRB030725/ This message may be cited.