TITLE: GCN CIRCULAR NUMBER: 35534 SUBJECT: GRB 240112C: Swift/UVOT Detection DATE: 24/01/14 18:22:22 GMT FROM: Paul Kuin at MSSL <npkuin@gmail.com> N. P. M. Kuin (UCL-MSSL) and Eyles-Ferris (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 240112C 121 s after the BAT trigger (Eyles-Ferris et al., GCN Circ. 35522). A source consistent with the XRT position is detected in the initial UVOT exposures. The preliminary UVOT position is: RA (J2000) = 18:02:34.58 = 270.64410 (deg.) Dec (J2000) = +24:29:21.3 = 24.48925 (deg.) with an estimated uncertainty of 0.43 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 white 121 236 113 16.98 +/- 0.04 v 4955 5126 169 >18.6 b 4340 4539 197 19.35 +/- 0.16 u 4134 4334 197 19.11 +/- 0.18 w1 3930 4129 197 19.13 +/- 0.24 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.108 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/35534. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...