TITLE: GCN CIRCULAR NUMBER: 22396 SUBJECT: GRB 180205A: Swift/UVOT Detection DATE: 18/02/06 12:58:32 GMT FROM: Sam Emery at MSSL-UCL S.W.K. Emery (UCL-MSSL) and P. A. Evans (U Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 180205A 182 s after the BAT trigger (Evans et al., GCN Circ. 22381). A fading source consistent with the XRT position (Page et al., GCN Circ. 22394), also detected by (Zheng et al. GCN 22382; Bolmer et al. GCN 22383; Tanvir et al. GCN 22384; Volnova et al. GCN 22387; Falcon et al. GCN 22390; Xin et al. 22392; Zhu et al. GCN 22395) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:27:16.74 = 126.81975 (deg.) Dec (J2000) = +11:32:30.9 = 11.54191 (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 first finding chart (FC) exposure and the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 182 331 147 15.75 +/- 0.02 white 540 732 36 16.33 +/- 0.02 v 158 612 52 16.11 +/- 0.09 b 515 710 39 16.65 +/- 0.07 u 490 686 39 16.82 +/- 0.07 uvw1 466 661 39 16.04 +/- 0.10 uvm2 441 636 39 16.32 +/- 0.15 uvw2 391 585 39 17.06 +/- 0.17 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).