GCN Circular 4368
Subject
GRB 051221: Improved astrometry of the IR counterpart
Event
Date
2005-12-21T07:20:22Z (21 years ago)
From
Josh Bloom at UC Berkeley <jbloom@astron.berkeley.edu>
J. S. Bloom (UC Berkeley) reports:
We have reduced the second epoch of our PAIRITEL imaging (beginning
2005-12-21 03:02:32 UTC; total integration = 690 sec) and detect the
source mentioned in GCN 4367 in a stacked mosaic. The source appears
to be best detected in the full stack J-band image at a revised
position of J2000:
21:54:48.662 +16:53:26.97
The uncertainty relative to the USNOB1.0 is 180 mas in each
coordinate (the previous two circulars were based upon an astrometric
match using far fewer 2MASS sources in the field). This position is
1.41 arcsec from the Burrows et al. XRT position (GCN 4366). Because
the source is observed near the detection level, we cannot confirm
fading behavior at this time. Still, given the proximity to the XRT
location, we advance that this source is the IR counterpart to GRB
051221 (GCN 4363). If so, this would be the first infrared
counterpart detected for a short-hard GRB.
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