{
  "circularId": 42446,
  "eventId": "GRB 251024A",
  "body": "M. H. Siegel 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 251024A 132 s after the BAT trigger (Moss et al., GCN Circ. 42426). No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 42430) is detected in the initial UVOT exposures.\n\nPreliminary 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:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite_FC           132          282          147         >21.0\nu_FC               290          540          246         >19.9\nwhite              132          591          167         >21.0\nv                  622          641           19         >18.0\nb                  547          567           20         >19.8\nu                  290          540          246         >19.9\nw2                 597          617           20         >19.2\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.044 in the direction of the burst\n(Schlegel et al. 1998).",
  "bibcode": "2025GCN.42446....1S",
  "createdOn": 1761423096690,
  "submittedHow": "web",
  "format": "text/plain",
  "subject": "GRB 251024A: Swift/UVOT Upper Limits",
  "submitter": "Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>"
}