TITLE: GCN CIRCULAR NUMBER: 6751 SUBJECT: GRB 070809: Swift/UVOT Corrected Photometry DATE: 07/08/10 20:54:59 GMT FROM: Margaret Chester at PSU M.M. Chester (PSU) and F.E. Marshall (NASA/GSFC) report on behalf of the Swift UVOT team: We have identified an additional exposure of GRB 070809 made by the Swift/UVOT that covers the XRT error circle, and can now provide an optical upper limit at a much earlier time, 74 seconds after the BAT trigger. In addition, an error in the photometry analysis previously reported (Chester et al., GCN Circ. 6744) has been identified, and corrected upper limits are reported below. Filter Tstart Tstop Exp Magnitude (s) (s) (s) (3-sigma UL) v (FC) 74 474 394 19.1 v 6344 18560 1251 20.2 b 5932 24593 614 20.4 u 5727 24363 1911 20.6 uvw1 5523 23449 2164 20.6 uvm2 5317 19316 2018 21.0 uvw2 6139 17646 1279 20.6