TITLE: GCN CIRCULAR NUMBER: 15454 SUBJECT: GRB 131105A: Swift/UVOT Upper Limits DATE: 13/11/05 11:40:36 GMT FROM: Massimiliano de Pasquale at MSSL-UCL M. De Pasquale (UCL-MSSL) and J. R. Cummings (NASA/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 131105A 295 s after the BAT trigger (Cummings et al., GCN Circ. 15446). No optical afterglow consistent with the optical position (Xu et al. GCN Circ. 15447) 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 295 444 147 >21.5 white 295 1544 353 >22.0 v 774 1594 97 >19.3 b 1152 1520 58 >19.9 u 848 1495 78 >19.8 w1 823 1471 78 >19.4 m2 798 1619 39 >18.4 w2 750 1570 78 >19.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).