TITLE: GCN CIRCULAR NUMBER: 42956 SUBJECT: GRB 251202A: Swift/UVOT Detection DATE: 25/12/02 16:35:43 GMT FROM: Paul Kuin at MSSL <npkuin@gmail.com> N.P.M. Kuin (UCL-MSSL) and M. J. Moss (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of EP251202a/GRB 251202A 17,500s after the EP trigger (Zhang et al., GCN Circ. No 42937). A source consistent with Li et al. (GCN Circ No 42934) and the XRT position (Sbarufatti et al. GCN Circ. No. 42943) is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 08:08:27.5 = 122.11420 (deg.) Dec (J2000) = 40:36:45.3 = 40.61244 (deg.) with an estimated uncertainty of 0.48 arc sec. (radius, 90% confidence). 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 u 17500 18104 509 19.80 +/- 0.20 u 23697 24044 342 20.26 +/- 0.39 u 28710 28841 129 20.06 +/- 0.53 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.043 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/42956. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...