TITLE: GCN CIRCULAR NUMBER: 13447 SUBJECT: GRB 120709A: Swift/UVOT Observations DATE: 12/07/11 20:20:12 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and C. A. Swenson (PSU) report on behalf of the Swift/UVOT team: Swift/UVOT began observations of GRB 120709A (Kocevski et al. GCN Circ. 13423) 16.7 hours after the trigger. Observations covered the central 16'x16' region of the 0.35 deg. radius LAT error circle with the White, U, and V filters. No credible afterglow candidate was seen in any of the exposures. The candidate X-ray afterglow from observations with Swift/XRT (Grupe and Swenson GCN Circ. 13428) is too near the edge of the UVOT images to do accurate photometry except for the 568-second white exposure starting 66.8 ks after the trigger and the 802-second U exposure starting 66.0 ks after the trigger. The catalogued optical source at the edge of the XRT error circle is clearly detected with UVOT, but there is no indication of any other source consistent with the XRT position. Preliminary magnitudes for the catalogued source and 3-sigma upper limits for positions well removed from the catalogued source using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are given below. Filter T_Start Exposure Source Mag Upper Limit (ks) (s) white 66.8 568 19.3 +/- 0.1 21.8 u 66.0 802 19.0 +/- 0.1 21.1