{
  "eventId": "GRB 231205B",
  "body": "M. H. Siegel (PSU) and P. A. Evans (U. Leicester)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 231205B\n216 s after the BAT trigger (Evans et al., GCN Circ. 35269).\nNo optical afterglow consistent with the XRT position\n(Osborne et al. 35275) 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\nwhite_FC           237          387          147         >21.3\nwhite              237          536          167         >21.3\nv                  216          414           33         >18.6\nb                  492          512           19         >19.6\nu                  468          487           19         >18.2\nw1                 443          463           19         >19.3\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.204 in the direction of the burst\n(Schlegel et al. 1998).",
  "submitter": "Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>",
  "bibcode": "2023GCN.35308....1S",
  "createdOn": 1702057133333,
  "circularId": 35308,
  "submittedHow": "web",
  "subject": "GRB231205B: Swift/UVOT Upper Limits"
}