TITLE: GCN CIRCULAR NUMBER: 10934 SUBJECT: GRB 100704: Swift/UVOT Upper Limits DATE: 10/07/04 15:22:17 GMT FROM: Patricia Schady at MPE/Swift N.P.M. Kuin (MSSL/UCL) and D. Grupe (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 100704 96 s after the BAT trigger (Grupe et al., GCN Circ. 10929). No optical afterglow consistent with the XRT position (Osborne et al., GCN Circ. 10930) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using a 3" aperture in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 96 246 147 >21.0 u_FC 308 558 246 >20.2 white 96 6544 746 >21.8 v 638 6955 471 >20.0 b 564 6339 452 >21.1 u 308 6132 678 >21.1 w1 688 5927 255 >21.1 m2 662 7075 387 >20.2 w2 613 6750 471 >20.7 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.17 in the direction of the burst (Schlegel et al. 1998).