{
  "circularId": 42954,
  "eventId": "GRB 251201B",
  "createdOn": 1764690748834,
  "bibcode": "2025GCN.42954....1K",
  "subject": "GRB 251201B: Swift/UVOT Detection",
  "submittedHow": "email",
  "submitter": "Paul Kuin at MSSL <npkuin@gmail.com>",
  "body": "N.P.M. Kuin  (UCL-MSSL) and M. J. Moss (GSFC) report on behalf of the\nSwift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 251201B  101\ns after the BAT trigger (Moss et al., GCN Circ. 42924).  A source\nconsistent with the XRT position is detected in the initial UVOT exposures.\n\nPreliminary detections and 3-sigma upper limits using the UVOT photometric\nsystem\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures\nare:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\n\nwhite              101          251          147         17.31 +/- 0.03\nv                  644          663           19         15.97 +/- 0.12\nb                  570          589           20         16.71 +/- 0.10\nu                  314          564          246         16.48 +/- 0.04\nw1                 693         1808          117         18.35 +/- 0.18\nm2                 668         1093           39        >18.7\nw2                1196         1562           39        >18.8\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.008 in the direction of the burst\n(Schlegel et al. 1998).\n"
}