GCN Circular 3969
A. A. Breeveld (UCL-MSSL), K. Page (U. Leicester), T. S. Poole (UCL-MSSL), F. Marshall (GSFC), M. Chester, P. Meszaros, J. Nousek (PSU) on behalf of the Swift/UVOT team: UVOT started observing GRB050911 16408 s (4.56 hours) after the burst (Page et al. GCN 3961). The delay was caused by firstly an earth limb constraint and then Swift spacecraft loss of lock on the star tracker. No new source was found within the XRT error circle (Page et al. GCN 3967) to the following upper limits. Filter T_range (s) Exp (s) 3sig UL V 21591-22041 900 20.2 B 16408-17291 883 21.0 B 28287-28870 583 20.8 U 27380-28280 900 20.9 UVW1 26473-27373 900 21.2 UVM2 22498-23081 583 20.9 UVW2 32261-32961 700 21.4 Where T_range is the time range post-trigger over which the summed images were accumulated and Exp is the total exposure time of the summed image. The magnitude upper limits are not corrected for extinction. This message may be cited.