TITLE: GCN CIRCULAR NUMBER: 19513 SUBJECT: GRB 160607A: Swift/UVOT Upper Limits DATE: 16/06/08 18:45:54 GMT FROM: Mike Siegel at PSU/Swift MOC 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 160607A 84 s after the BAT trigger (Ukwatta et al., GCN Circ. 19502). No optical afterglow consistent with the enhanced XRT position (Goad et al., GCN Circ. 19503) nor at the position of the NOT source (Malesani et al., GCN 19507), 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 84 233 147 >20.4 u_FC 296 546 246 >19.9 white 84 1658 299 >20.6 v 626 1707 117 >18.7 b 552 1633 115 >19.5 u 296 1088 393 >19.9 w1 849 1237 39 >19.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).