TITLE: GCN CIRCULAR NUMBER: 26164 SUBJECT: GRB 191101A: Swift/UVOT Upper Limits DATE: 19/11/04 19:01:00 GMT FROM: Sam LaPorte at PSU GRB 191101A: Swift/UVOT Upper Limits S. J. LaPorte (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 191101A 110 s after the BAT trigger (D'Ai et al., GCN Circ. 26135). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 26140) 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 110 259 147 >21.1 u_FC 268 517 246 >20.3 white 110 5863 589 >21.6 v 597 1588 110 >19.6 b 523 5658 294 >21.2 u 268 5453 540 >20.9 w1 646 5248 294 >19.3 m2 622 5043 300 >19.8 w2 573 1564 117 >19.3 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).