GCN Circular 15362
S. R. Oates (MSSL-UCL) 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 131018B 83 ks after the LAT trigger (Vianello et al., GCN Circ. 15357). No new optical candidate is detected within the LAT error circle (Vianello et al., GCN Circ. 15357) in the initial UVOT exposures. We note an optical source within the error circle of the candidate XRT position (D'Avanzo et al., GCN Circ. 15361), which is found in the USNO-B1 catalogue. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 90363 91160 785 >21.7 v 91168 91427 255 >19.4 u 88969 95244 1300 >20.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.58 in the direction of the burst (Schlegel et al. 1998).