TITLE: GCN CIRCULAR NUMBER: 16541 SUBJECT: GRB 140706A: Swift/UVOT Detection DATE: 14/07/07 23:46:26 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU) and F. E. Marshall (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140706A 82 s after the BAT trigger (Marshall et al., GCN Circ. 16531). A fading source consistent with the XRT position (Beardmore et al. GCN Circ. 16532) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 03:17:10.39 = 49.29328 (deg.) Dec (J2000) = -38:03:07.8 = -38.05218 (deg.) with an estimated uncertainty of 0.45 arc sec. (radius, 90% confidence). 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 (fc) 82 232 147 19.04 +/- 0.06 white 573 1541 244 19.76 +/- 0.16 v 624 1592 117 >18.8 b 550 1517 97 >19.2 u (fc) 294 544 246 19.02 +/- 0.11 u 624 1591 116 >19.6 w1 674 1638 94 >19.1 w2 775 1394 58 >20.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).