TITLE: GCN CIRCULAR NUMBER: 31222 SUBJECT: GRB 211211A: Swift/UVOT detection DATE: 21/12/12 18:19:57 GMT FROM: Alexander Belles at PSU/Swift A. Belles (PSU) and A. D'Ai (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 211211A 92 s after the BAT trigger (D'Ai et al., GCN Circ. 31202). A fading source consistent with the XRT position (Beardmore et al. GCN Circ. 31205) and optical position (Zheng & Filippenko, GCN Circ. 31203) is detected in the initial UVOT exposures. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag wh_FC 92 242 147 18.93+/-0.22 wh 3906 4106 196 18.33+/-0.09 wh 68215 68397 179 >19.74 b 3701 3901 196 18.97+/-0.28 b 16837 17437 587 19.27+/-0.28 b 67303 68210 885 19.70+/-0.24 v 4317 4517 196 >18.33 u 3496 5012 275 18.26+/-0.16 u 15924 16831 885 18.44+/-0.11 u 57177 74247 362 >18.89 w1 4727 4927 196 17.46+/-0.16 m2 4522 4721 196 17.58+/-0.19 m2 21678 22153 467 18.18+/-0.18 w2 4112 4312 196 17.30+/-0.15 w2 61756 62656 885 18.94+/-0.24 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.018 in the direction of the burst (Schlegel et al. 1998).