GCN Circular 9967
Subject
GRB 090929B: RAPTOR Discovery of Optical Counterpart
Date
2009-09-29T16:46:34Z (15 years ago)
From
James Wren at LANL <jwren@nis.lanl.gov>
J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis, B. Norman
of Los Alamos National Laboratory report:
The RAPTOR telescope system responded to Swift trigger
371050 (Pagani et al., GCN 9963) under good observing conditions.
Our narrow-field instruments began observing the location at
10:20:53.37 UTC, 11.77 minutes after the initial BAT trigger.
Our initial images show an R~16.8 optical counterpart at the enhanced
XRT location (Page et al., GCN 9965). The object fades steadily
reaching R~18.0 at 10:50 UTC. Our unfiltered images were calibrated
against the USNO-B1 R-band. Unfortunately, an 11th magnitude star is
only 19 arcseconds away, limiting our photometric accuracy. Further
analysis is ongoing.