TITLE: GCN CIRCULAR NUMBER: 19231 SUBJECT: GRB 160325A: Further Swift/UVOT Observations DATE: 16/03/25 22:40:00 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) and E. Sonbas (Adiyaman Univ.) report on behalf of the Swift/UVOT team: We report further on the Swift/UVOT observations of GRB 160325A which began 75 s after the BAT trigger (Sonbas et al., GCN Circ. 19222). A source was reported earlier by McCauley et al. (GCN Circ. 19228), which was consistent with the XRT position (Evans et al., GCN Circ. 19229) and infrared detection (Fugazza et al., GCN Circ. 19223). We confirm that the source is rapidly fading. 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 75 224 146 15.65+-0.05 white 567 1187 205 17.24+-0.05 white 7227 12203 231 19.59+-0.16 v 617 809 38 15.12+-0.07 v 1044 1237 38 15.79+-0.10 v 1392 6402 216 17.73+-0.14 b 543 735 38 17.11+-0.11 b 1143 1510 58 18.70+-0.33 b 7023 7222 196 >19.64 u 287 537 245 18.91+-0.22 u 691 7017 274 >19.47 uvw1 666 1461 97 18.36+-0.32 uvw1 6613 6812 196 19.05+-0.33 uvm2 641 1263 77 18.30+-0.34 uvm2 1416 6607 216 18.73+-0.29 uvw2 593 1387 97 >18.63 uvw2 5998 6197 196 18.30+-0.19 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).