GCN Circular 4390
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.