TITLE: GCN CIRCULAR NUMBER: 19412 SUBJECT: GRB 160509A: Swift/UVOT Upper Limit DATE: 16/05/09 17:54:45 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and T.G.R. Roegiers (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the Swift-XRT afterglow (Kennea et al., GCN Circ. 19408) 7259 s after the LAT trigger (Longo et al., GCN Circ. 19403). No UVOT source consistent with the position of Swift-XRT afterglow or the position of the optical afterglow candidate (Levan et al., GCN Circ. 19410) is found in the initial exposure. The preliminary upper limit using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) is: Filter T_start(s) T_stop(s) Exp(s) Mag u 7259 7531 268 >20.5 The magnitude in the table is not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.31 in the direction of the burst (Schlegel et al. 1998).