TITLE: GCN CIRCULAR NUMBER: 22779 SUBJECT: GRB 180613A: Swift/UVOT Upper Limits DATE: 18/06/14 19:10:11 GMT FROM: Mike Siegel at PSU/Swift MOC S. Sebzda (PSU) and A. Tohuvavohu (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 180613A 156 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22769). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 22773) 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 u_FC 156 405 246 >20.4 v 461 24234 1434 >20.9 b 411 13230 1022 >99.0 u 156 18973 2109 >21.8 w1 510 18472 2212 >21.2 m2 486 24474 1627 >21.0 w2 1036 23321 1318 >20.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.09 in the direction of the burst (Schlegel et al. 1998).