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GCN Circular 14177

GRB 130131A: RAPTOR Limits During Gamma-Ray Emitting Interval
2013-02-01T19:23:05Z (11 years ago)
James Wren at LANL <>
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 547407 (Grupe, et al., GCN 14156).  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 13:56:20.65 UT, 1.4 s before the Swift trigger
time and during the gamma-ray emitting interval.  During the period that the
BAT was detecting gamma-ray emission, from ~T-5 s to ~T+65 s (Palmer,
et al., GCN 14163), we have a total of four 10 s exposures with limiting
magnitudes of R~9.4 in moderate moonglow.  We do not detect the optical
counterpart (Tanvir et al., GCN 14157; Virgili et al., GCN 14158) in any of
our images.  Our 3-sigma limiting magnitudes are based on a comparison of
our unfiltered image to the Tycho-2 V-band catalog.
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