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GCN Circular 15815

GRB 140209A: Early RAPTOR Optical Detection
2014-02-10T19:32:06Z (10 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 follow-up observations
of Swift trigger 586071 (Cenko, et al., GCN 15808).  Our narrow-field
instruments in Los Alamos, NM, began imaging at 07:31:24.33 UT,
26.5 seconds after the BAT trigger time.  We clearly detect the optical
counterpart (Perley, et al., GCN 15809).  Our first image at Tmid-Tbat=29.0s
shows the counterpart at an unfiltered magnitude of 14.43+-.04.  The
counterpart fades steadily to mag 15.50+-.08 by Tmid-Tbat=65.4s.  Our
unfiltered observations were calibrated to the USNO-B1 R-band.
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