TITLE: GCN CIRCULAR NUMBER: 22483 SUBJECT: GRB 180314A: Swift/UVOT Detection DATE: 18/03/14 11:49:54 GMT FROM: Samantha Oates at MSSL S. R. Oates (U.Warwick) and P. D'Avanzo (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 180314A 167 s after the BAT trigger (D'Avanzo et al., GCN Circ. 22478). A source consistent with the XRT position (Osborne et al. GCN Circ. 22480) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 06:37:03.68 = 99.26535 (deg.) Dec (J2000) = -24:29:46.0 = -24.49610 (deg.) with an estimated uncertainty of 0.42 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(FC) 167 317 147 16.28 +/- 0.03 white 606 626 19 17.86 +/- 0.15 v 829 849 19 17.07 +/- 0.25 b 755 774 19 18.09 +/- 0.28 u 326 576 246 16.95 +/- 0.06 w1 705 1131 39 17.98 +/- 0.33 m2 680 1106 58 18.12 +/- 0.35 w2 631 1578 117 18.75 +/- 0.30 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.08 in the direction of the burst (Schlegel et al. 1998). --------------------------------------------- Dr Samantha Oates Leverhulme Early Career Fellow Department of Physics University of Warwick Coventry CV4, UK Tel: +44 (024) 765 23383 Email: s.oates@warwick.ac.uk -----------------------------------------------