TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4342 SUBJECT: GRB 051211A: Swift/UVOT upper limits DATE: 05/12/12 15:48:34 GMT FROM: Alexander Blustin at MSSL-UCL A. J. Blustin (UCL-MSSL), G. Cusumano (INAF-IASF), J. Greiner (MPE), D. Hinshaw (GSFC-SPSYS), N. Gehrels (GSFC) on behalf of the Swift/UVOT team The Swift/UVOT began observing the field of GRB 051211a at 15:50:04 UT on 2005-12-11, 13 hours after the HETE trigger (Atteia et al., GCN 4324). No potential optical/UV counterpart was found in co-added images in any of the filters, within the reported 80 arcsec radius (90% confidence) HETE error circle, down to the following 5-sigma magnitude upper limits (not corrected for extinction). Filter T_range(hours) Exp(s) 5sigUL(mag) V 14.9-15.1 886 19.4 B 13.5-13.7 738 20.2 U 13.3-16.7 1469 20.3 W1 13.0-16.5 1800 20.0 M2 11.9-15.3 1502 20.1 W2 14.6-14.9 900 20.1