{
  "subject": "GRB 250706A: Swift/UVOT Upper Limits",
  "submittedHow": "web",
  "bibcode": "2025GCN.41008....1S",
  "createdOn": 1751892663957,
  "eventId": "GRB 250706A",
  "submitter": "Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>",
  "body": "M. H. Siegel (PSU) and M. J. Moss (GSFC) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 250706A\n147 s after the BAT trigger (Moss et al., GCN Circ. 40988).\nNo optical afterglow consistent with the XRT position is detected in the initial UVOT exposures.\nPreliminary 3-sigma upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first\nfinding chart (FC) exposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nu_FC               147          397          246         >19.5\nv                  453          473           19         >16.8\nb                  403          423           19         >18.0\nu                  147          397          246         >19.5\nw1                 502          509            6         >18.2\nm2                 477          497           19         >17.9\nw2                 429          449           19         >19.9\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.093 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 41008,
  "format": "text/plain"
}