TITLE: GCN CIRCULAR NUMBER: 14339 SUBJECT: GRB 130327A: Swift/UVOT Upper Limits DATE: 13/03/27 14:22:35 GMT FROM: Craig Swenson at PSU/Swift C. A. Swenson (PSU) and T. N. Ukwatta (MSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 130327A 104 s after the BAT trigger (Ukwatta et al., GCN Circ. 14331). No optical afterglow consistent with the XRT position (Osborne et al. GCN Circ. 14335) 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 104 254 147 >21.2 u_FC 317 567 246 >20.0 white 104 6491 727 >21.8 v 646 6877 428 >19.8 b 572 6286 432 >20.7 u 317 6081 659 >20.4 w1 695 12014 1111 >21.6 m2 671 11107 1141 >21.0 w2 622 6696 452 >21.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.13 in the direction of the burst (Schlegel et al. 1998).