TITLE: GCN CIRCULAR NUMBER: 5711 SUBJECT: GRB 061006: Swift/UVOT optical observations DATE: 06/10/07 20:33:52 GMT FROM: Shashi Pandey at MSSL S. B. Pandey and P. Schady (MSSL-UCL) report on behalf of the Swift-UVOT team: The Swift UVOT began observing the GRB 061006 field (trigger 232585), 129 seconds after the BAT trigger (GCN 5699). No new source was detected in the co-added UVOT observations down to the following 3-sigma magnitude upper limits within the refined XRT error circle (GCN 5703): Filter T_range (s) Exposure (s) 3sigma UL V 129-18315 2131 20.85 B 617-30237 789 21.23 U 593-45827 2534 21.86 W1 569-41793 2902 21.50 M2 545-35908 3462 21.69 W2 633-17402 1318 21.12 T_range is calculated from the time of the burst. The upper limits are not corrected for Galactic extinction E(B-V) = 0.32 mag along the line of sight to the burst.