TITLE: GCN CIRCULAR NUMBER: 6744 SUBJECT: GRB 070809: Swift/UVOT Upper Limits DATE: 07/08/10 16:10:59 GMT FROM: Margaret Chester at PSU M.M. Chester (PSU) and F.E. Marshall (NASA/GSFC) report on behalf of the Swift UVOT team: The Swift/UVOT observed the field of GRB 070809 (Marshall et al., GCN Circ. 6728) beginning 2007-08-09, 20:50:54, 5317 seconds after the BAT trigger. We do not find any new source in any of the UVOT observations inside the Swift/XRT error circle (RA,DEC(J2000)= 203.7708, -22.1408). The 3-sigma upper limits for detecting a source inside the XRT error circle in the co-added frames are: Filter Tstart Tstop Exp Magnitude (s) (s) (s) (3-sigma UL) v 6344 18560 1251 20.8 b 5932 24593 614 21.3 u 5727 24363 1911 21.7 uvw1 5523 23449 2164 21.7 uvm2 5317 19316 2018 21.7 uvw2 6139 17646 1279 21.6 The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.09 mag in the direction of the burst (Schlegel et al. 1998).