TITLE: GCN CIRCULAR NUMBER: 19398 SUBJECT: GRB 160506A: Swift/UVOT Upper Limits DATE: 16/05/06 15:13:11 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 160506A 102 s after the BAT trigger (Hagen et al., GCN Circ. 19394). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 19395) 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 v 407 2279 233 >19.36 b 357 2229 252 >20.37 u_FC 101 351 245 >20.13 u 101 2353 626 >20.58 uvw1 457 2329 233 >19.75 uvm2 432 2304 233 >19.52 uvw2 383 2255 252 >19.86 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.26 in the direction of the burst (Schlegel et al. 1998).