TITLE: GCN CIRCULAR NUMBER: 15527 SUBJECT: GRB 131127A: Swift/UVOT Upper Limits DATE: 13/11/28 11:56:24 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and C. B. Markwardt (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 131127A 102 s after the BAT trigger (Markwardt et al., GCN Circ. 15516). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 15520) nor the RATIR position (Butler et al. GCN Circ. 15525) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 102 252 147 >21.4 u_FC 315 565 246 >20.6 white 102 6711 746 >22.3 v 645 7024 373 >20.3 b 571 6506 452 >21.2 u 315 6300 678 >21.1 w1 694 6095 432 >20.6 m2 669 5890 269 >20.1 w2 621 6916 471 >20.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.14 in the direction of the burst (Schlegel et al. 1998).