TITLE: GCN CIRCULAR NUMBER: 19239 SUBJECT: GRB 160327A: Swift/UVOT Upper Limits DATE: 16/03/28 13:55:52 GMT FROM: Marissa McCaule at PSU L. M. McCauley (PSU) and J. L. Racusin (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160327A 71 s after the BAT trigger (Racusin et al., GCN Circ. 19235). No optical afterglow consistent with the XRT position (Goad et al. GCN Circ. 19237) 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 71 221 147 >21.06 u_FC 284 534 246 >20.52 white 71 5902 535 >21.50 v 613 6310 451 >19.66 b 539 5702 254 >20.38 u 283 6918 670 >20.66 uvw1 662 6721 412 >20.21 uvm2 637 1088 58 >18.49 uvw2 589 1039 38 >18.61 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).