TITLE: GCN CIRCULAR NUMBER: 12148 SUBJECT: GRB 110709A: Swift/UVOT Upper Limits DATE: 11/07/11 18:54:50 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC S. T. Holland (CRESST/USRA/GSFC) reports on behalf of the Swift/UVOT team: The Swift/UVOT observed the field of GRB 110709A starting 56 s after the BAT trigger (Holland et al., 2011, GCNC 12118). Settled observations started at 74 s. We do not detect an optical afterglow at the UVOT-enhanced XRT position (Osborne, et al., 2011, GCNC 12123) in any of the UVOT filters. Preliminary 3-sigma upper limits for detecting a source in the finding charts and in the co-added images, are Filter TSTART TSTOP ESPOSURE Mag --------------------------------------------------- white (FC) 74 224 147 >21.7 u (FC) 287 536 246 >21.0 white (FC) 865 1014 147 >21.8 --------------------------------------------------- v 616 7409 549 >20.9 b 542 19,323 2148 >22.5 u 287 18,560 2337 >22.2 uvw1 666 17,646 1383 >21.7 uvm2 5978 7614 393 >20.7 uvw2 591 7204 490 >21.2 white 74 13,546 1538 >23.1 --------------------------------------------------- The quoted magnitudes and upper limits have not been corrected for the large, but uncertain, Galactic extinction along the line of sight to this burst (E_{B-V} = 0.02 mag, Schlegel et al. 1998, ApJS, 500, 525).