TITLE: GCN CIRCULAR NUMBER: 17017 SUBJECT: GRB 141031B: Swift/UVOT Upper Limits DATE: 14/11/01 11:09:58 GMT FROM: Samantha Oates at MSSL S. R. Oates (IAA-CSIC/UCL-MSSL) and B. P. Gompertz (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 141031B 120 s after the BAT trigger (Gompertz et al., GCN Circ. 16998). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 17009) 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 120 270 147 >21.0 u_FC 278 528 246 >20.3 white 120 6181 580 >21.8 v 608 11035 1317 >20.6 b 534 5976 432 >20.9 u 278 5771 659 >20.9 w1 658 12348 620 >20.7 m2 633 11940 1121 >20.9 w2 584 6386 432 >20.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.14 in the direction of the burst (Schlegel et al. 1998).