GCN Circular 4390
Subject
GRB 051221A: Detection at 251nm with Swift UVOT
Date
2005-12-23T19:05:11Z (19 years ago)
From
Pete Roming at PSU <roming@astro.psu.edu>
P. Roming (PSU), A. A. Breeveld (UCL-MSSL), F. Marshall, A. Parsons, R.
Fink (GSFC), & M. Ajello (MPE) on behalf of the Swift/UVOT team:
We have created a summed image from 2.78 ksec of exposure on GRB051221A
(Parsons et al., GCN 4363) through the "UVW1" filter of the Swift UVOT.
From the summed image we detect a source at 4.8-sigma confidence with a
position coincident with the one reported by Bloom (GCN 4367) and Berger
(GCN 4369). The magnitude of the source is 20.2+/-0.2 as determined by the
Swift analysis tool, uvotsource.
Examination of individual frames suggests that the source is not
distinguishable above background in the individual short (50-s and 100-s)
exposures and is only visible at the 3-sigma level in one of the early ~600
second exposures of the sequence.