TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4089 SUBJECT: GRB 051006: Swift/UVOT Upper Limits DATE: 05/10/12 14:23:12 GMT FROM: Stephen Holland at USRA/NASA/GSFC/SSC GRB 051006: Swift/UVOT Upper Limits S. T. Holland (GSFC/USRA), J. Norris (GSFC), J. Greiner (MPE), D. Hinshaw (GSFC-SPSYS), and N. Gehrels (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began observing the field of GRB 051006 107 seconds after the BAT trigger (Norris et al. GCN 4061). No new source is detected at the position of the XRT error circle (Capalbi et al. GCN 4066) in the initial 200 second V-band image down to a 5-sigma upper limit of 18.3, or in summed exposures with any of the filters down to the following 5-sigma magnitude upper limits. Filter T_range (s) Exp (s) 5sig UL V 107 - 98,547 12,033 20.5 B 474 - 68,573 4,111 20.9 U 420 - 64,478 3,846 20.4 UVW1 366 - 63,741 4,598 21.0 UVM2 311 - 73,819 4,179 21.3 UVW2 582 - 69,481 5,448 21.6 WHITE 527 - 577 50 18.5 These magnitudes have not been corrected for extinction.