TITLE:   GCN CIRCULAR
NUMBER:  13815
SUBJECT: GRB 120923A: RAPTOR Limits During Gamma-Ray Emitting Interval
DATE:    12/09/24 22:42:24 GMT
FROM:    James Wren at LANL  <jwren@nis.lanl.gov>

J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis,
of Los Alamos National Laboratory report:

The RAPTOR network of robotic optical telescopes made observations of Swift
trigger 534402 (Yershov, et al., GCN 13796).  The burst location was within
the field of our wide-field monitor located in Maui, HI, which began a 10 s
integration of the location at 05:16:05.26 UT, 1.0 s before the Swift trigger
time and during the gamma-ray emitting interval.  The next 10 s exposure began
at 05:16:23.26, 17.0 s after the Swift trigger and covering the peak emission
detected by the BAT (Markwardt, et al., GCN 13807).  The optical counterpart
(Levan, et al., GCN 13802) was not detected above our 3-sigma limiting
magnitude of 10.5 based on a comparison of our unfiltered image to the
Tycho-2 V-band catalog.