TITLE: GCN CIRCULAR NUMBER: 42353 SUBJECT: GRB 251018A: Swift/UVOT Detection DATE: 25/10/18 11:57:31 GMT FROM: Paul Kuin at MSSL <npkuin@gmail.com> N.P.M. Kuin (MSSL-UCL) and R. Gupta (NASA GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 251018A 84 s after the BAT trigger (Gupta et al., GCN Circ. 42343). A source consistent with the XRT position is detected in the initial UVOT exposures. 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 84 128 44 17.98 +/- 0.08 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.101 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/42353. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...