TITLE: GCN CIRCULAR NUMBER: 17820 SUBJECT: GRB 150514A: Swift/UVOT Detection DATE: 15/05/15 13:50:53 GMT FROM: Frank Marshall at GSFC F. E. Marshall (NASA/GSFC) and J. K. Cannizzo (GSFC/UMBC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150514A 40750 s after the LAT trigger (Kocevski and Arimoto, GCN Circ. 17816). A source consistent with the XRT position (Kennea et al. GCN Circ. 17818) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 04:59:30.30 = 74.87623 (deg.) Dec (J2000) = -60:58:06.3 = -60.96841 (deg.) with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence). Preliminary detections 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 41402 41850 440 18.60 +/- 0.04 v 42049 42222 170 18.71 +/- 0.20 u 40750 41396 636 18.20 +/- 0.05 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).