TITLE: GCN CIRCULAR NUMBER: 41008 SUBJECT: GRB 250706A: Swift/UVOT Upper Limits DATE: 25/07/07 12:51:03 GMT FROM: Mike Siegel at PSU/Swift MOC <mhs18@psu.edu> M. H. Siegel (PSU) and M. J. Moss (GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 250706A 147 s after the BAT trigger (Moss et al., GCN Circ. 40988). No optical afterglow consistent with the XRT position 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 u_FC 147 397 246 >19.5 v 453 473 19 >16.8 b 403 423 19 >18.0 u 147 397 246 >19.5 w1 502 509 6 >18.2 m2 477 497 19 >17.9 w2 429 449 19 >19.9 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.093 in the direction of the burst (Schlegel et al. 1998). View this GCN Circular online at https://gcn.nasa.gov/circulars/41008. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...