TITLE: GCN CIRCULAR NUMBER: 13947 SUBJECT: GRB 121031A: Swift/UVOT Upper Limits DATE: 12/11/02 18:26:47 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 121031A 70 s after the BAT trigger (D'Elia et al., GCN Circ. 13934). No optical afterglow consistent with the enhanced XRT position (Goad et al., GCN Circ. 13944) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 70 220 147 >19.9 white 5366 7002 393 >20.5 v 5776 11730 787 >19.4 b 5161 18152 492 >20.0 u 16939 17239 295 >19.5 w1 4751 16932 1279 >20.5 m2 4545 22572 1870 >21.1 w2 5572 11120 1082 >20.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).