Skip to main content
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 14076

GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval
2012-12-13T01:06:51Z (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 541371 (Grupe, et al., GCN 14064).  The burst location was within
the field of our wide-field monitor located near Los Alamos, NM USA, which
began a 10 s exposure of the location at 06:56:03.18 UT, 10.2 s before the
Swift trigger time and covering the initial few seconds of gamma-ray emission
as detected by the BAT (Barthelmy, et al., GCN 14068).  The next 10 s exposure
begins at 06:56:23.58 UT, 10.2 s after the Swift trigger time and overlapping
the end stages of the gamma-ray emission.  We do not detect the optical
counterpart detected by the UVOT (Kuin, et al., GCN 14069) and others.  Our
3-sigma limiting magnitudes are R~10.1 based on comparison of our unfiltered
images to the Tycho-2 V-band catalog.

Our narrow-field instruments began a series of 10 s exposures at 06:58:08.59
UT, 115 s after the Swift trigger.  These images also do not show the optical
counterpart to a limiting magnitude of R~16.4 based on comparison to the
USNO-B1 R-band.
Looking for U.S. government information and services? Visit