TITLE: GCN CIRCULAR NUMBER: 12434 SUBJECT: GRB 111008A: Swift/UVOT Upper Limits DATE: 11/10/09 18:37:31 GMT FROM: Paul Kuin at MSSL N. P. M. Kuin (MSSL-UCL) and C. J. Saxton (UCL-MSSL) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 111008A 99 s after the BAT trigger (Saxton et al., GCN Circ. 12423). No optical afterglow consistent with the refined XRT position (Beardmore et al., GCN 12425; see also Levan et al. GCN 12426, Nardini et al. GCN 12428, and Wiersema et al. GCN 12431) is detected in the initial UVOT exposures, consistent with the redshift reported by Levan et al. and Wiersema et al.. Preliminary 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 99 249 147 >21.3 u_FC 311 561 246 >20.5 white 99 1359 373 >21.8 v 641 1409 97 >19.0 b 566 1335 78 >19.7 u 311 1310 304 >20.6 w1 690 1457 77 >19.2 m2 666 1433 97 >21.0 w2 617 1385 97 >19.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).