TITLE: GCN CIRCULAR NUMBER: 36870 SUBJECT: GRB 240712A: Swift/UVOT Upper Limits DATE: 24/07/15 15:26:44 GMT FROM: Paul Kuin at MSSL <npkuin@gmail.com> N. P. M. Kuin (UCL-MSSL) and C. Salvaggio (INAF-OAB) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 240712A 141 s after the BAT trigger (Salvaggio et al., GCN Circ. 36851). No optical afterglow consistent with the XRT position in GCN Circ 36851 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 141 290 147 >20.2 u_FC 299 549 246 >19.9 white 141 1550 392 >21.0 v 629 5288 179 >19.0 b 555 1525 97 >20.0 u 299 1500 324 >20.3 w1 678 1476 97 >19.2 m2 653 1451 97 >18.7 w2 604 5200 313 >19.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.996 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/36870. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...