TITLE: GCN CIRCULAR NUMBER: 22086 SUBJECT: GRB 171102B: Swift/UVOT Upper Limits DATE: 17/11/03 05:32:40 GMT FROM: Sam LaPorte at PSU GRB 171102B: Swift/UVOT Upper Limits S. J. LaPorte (PSU) and T. N. Ukwatta (LANL) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 171102B 125 s after the BAT trigger (Ukwatta et al., GCN Circ. 22082). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 22084) 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 4979 5129 147 >20.2 u_FC 125 375 246 >19.8 white 4979 5749 344 >20.5 v 432 11930 1160 >19.3 b 381 18368 1057 >20.5 u 125 24106 2391 >21.5 w1 481 23421 2042 >20.7 m2 456 22515 1843 >21.3 w2 407 11017 1179 >20.7 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.75 in the direction of the burst (Schlegel et al. 1998).