TITLE: GCN CIRCULAR NUMBER: 21351 SUBJECT: GRB 170714A: Swift/UVOT Observations DATE: 17/07/17 19:28:04 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and A. D'Ai (INAF-IASFPA) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 170714A 384 s after the BAT trigger (D'Ai et al., GCN Circ. 21340). There is weak evidence for a fading source consistent with the position of the z-band afterglow candidate reported by de Ugarte Postigo et al. (GCN Circ. 21346). Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag v 384 1695 175 >18.6 b 496 1644 155 20.0 +/- 0.33 b 5390 24672 1011 >20.3 u 471 1619 284 20.1 +/- 0.35 u 5185 30412 2351 20.4 +/- 0.18 u 81432 92912 1509 >20.7 w1 446 1594 136 >21.0 m2 6006 29000 2637 >20.9 w2 5596 34449 3032 >22.0 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998). [GCN OPS NOTE(17jul17): Per author's request, please see GCN Circ 21353 for corrections to the above table.]