TITLE: GCN CIRCULAR NUMBER: 15708 SUBJECT: GRB 140108A: Swift/UVOT Detection DATE: 14/01/09 12:31:27 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and J. L. Racusin (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140108A 78 s after the BAT trigger (Racusin et al., GCN Circ. 15699). A fading source consistent with the optical position (Gorbovskoy et al. GCN Circ. 15701, Strobl et al. GCN Circ. 15703) is detected in the initial UVOT exposures. The preliminary detection and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the finding chart (FC) and other early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 78 228 147 20.17 ± 0.20 white 571 1021 189 >21.3 v 621 1420 97 >18.9 b 547 1345 78 >19.8 u 291 1320 304 >20.6 w1 670 1462 90 >20.3 m2 646 1444 97 >19.8 w2 596 1395 83 >20.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 1.00 in the direction of the burst (Schlegel et al. 1998).