TITLE: GCN CIRCULAR NUMBER: 19291 SUBJECT: GRB 160411A: Swift/UVOT Upper Limits DATE: 16/04/11 17:40:56 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and K. L. Page (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160411A 3139 s after the BAT trigger (Page et al., GCN Circ. 19279). No optical afterglow consistent with the XRT position (Perri et al. GCN Circ. 19281) 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 3139 3289 147 >20.5 white 3139 4521 344 >21.0 v 3295 4931 393 >19.4 b 4116 4316 197 >19.9 u 3910 5546 393 >20.0 w1 3705 5342 393 >20.2 m2 3500 5136 393 >20.1 w2 4527 4726 197 >20.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).