GCN Circular 35134
N.P.M. Kuin (MSSL/UCL) and S. L. Laha (GSFC/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 231117A 106 s after the BAT trigger (Laha et al., GCN Circ. 35071). A source consistent with the XRT position (Beardmore et al., GCN Circ. 35074 is detected in the initial UVOT exposures. Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 106 1713 392 21.21 +/- 0.27 v 648 1418 78 >18.8 b 574 1688 78 >19.3 u 318 741 265 >19.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.071 in the direction of the burst (Schlegel et al. 1998).