TITLE: GCN CIRCULAR NUMBER: 11795 SUBJECT: GRB 110315A: Swift/UVOT Upper Limits DATE: 11/03/16 15:54:41 GMT FROM: Erik Hoversten at Swift/Penn State E. A. Hoversten (PSU) and A. Melandri (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 110315A 113 s after the BAT trigger (Melandri et al., GCN Circ. 11790). No optical afterglow consistent with the enhanced XRT position (Beardmore et al., GCN Circ. 11792) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using 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 113 263 147 >20.5 u_FC 325 559 230 >19.7 white 113 12119 1275 >21.8 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.25 in the direction of the burst (Schlegel et al. 1998).