GCN Circular 4215
Subject
GRB 051109a: MDM Observations
Date
2005-11-09T03:52:12Z (20 years ago)
From
Jules Halpern at Columbia U. <jules@astro.columbia.edu>
N. Mirabal (U. Michigan), J. P. Halpern, and S. Tonnesen (Columbia U.)
report on behalf of the MDM Observatory GRB follow-up team:
"We are observing the afterglow of Swift GRB 051109 detected by ROTSE-IIIb
(Rykoff et al. GCN #4211, Schaefer et al. GCN #4214) using the MDM 2.4m
telescope and a Gunn r filter under partly cloudy conditions. From 38 minutes
to 148 minutes after the burst, the OT faded from R = 18.21 +/- 0.05 to
R = 19.22 +/- 0.08. Magnitudes are referenced to a USNO B1.0 star at
22h01m14.60s +40d49'25.3" (J2000) having R=17.23. This corresponds to a
power-law decay index of -0.68. Observations are continuing."