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GCN Circular 12992

GRB 120227A: RAPTOR Limit During the Gamma-Ray Emitting Interval
2012-02-27T22:06:54Z (12 years ago)
James Wren at LANL <>
J. Wren, W. T. Vestrand, P. Wozniak, and H. Davis
of Los Alamos National Laboratory report:

The RAPTOR wide-field optical monitor located in Maui was observing the
location of GRB 120227A which occured at 09:22:46 UT (Fermi GBM trigger
352027367, INTEGRAL SPI-ACS trigger 6478).  Our system covered the entire
6.33 degree radius statistical error region specified in the Fermi-GBM
Final Position GCN notice.  The image that was coincident with the trigger
started at 09:22:40.6 UT with an exposure duration of 10 seconds.  This
unfiltered image has a 3-sigma limiting magnitude of approximately 10.3
when compared to the Tycho-2 V-band.  A visual inspection of this image
when differenced with one taken 17 minutes later does not show any candidate
optical counterparts within the specified error region.
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