{
  "version": 2,
  "format": "text/plain",
  "submittedHow": "email",
  "createdOn": 1759746047467,
  "submitter": "Paul Kuin at MSSL <npkuin@gmail.com>",
  "eventId": "GRB 251005C",
  "bibcode": "2025GCN.42121....1K",
  "body": "N. P. M. Kuin (MSSL/UCL) and K. L. Page (U. Leicester)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 251005C 123 s\nafter the BAT trigger (Page et al., GCN Circ. 42113).\nNo optical afterglow consistent with the XRT position is detected in the\ninitial UVOT exposures.\nPreliminary 3-sigma upper limits using the UVOT photometric system (Breeveld\net al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC)\nexposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite_FC           123          273          147         >21.6\nu_FC               336          586          246         >19.9\nwhite              123         1536          392         >21.3\nv                  666         1586          117         >19.4\nb                  592         1676          108         >19.8\nu                  336         1659          343         >20.0\nw1                 715         1461           78         >19.4\n\nThe magnitudes in the table are not corrected for the Galactic extinction due\nto the reddening of E(B-V) = 0.461 in the direction of the burst (Schlegel\net al. 1998).\n\nPlease note that the initial GCN (Page et al., GCN Circ. 42113) reported\n251005A \"A-burst\", which was corrected to \"C\" : GRB 251005C.\n",
  "editedOn": 1776181451691,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>",
  "circularId": 42121,
  "subject": "GRB 251005C: Swift/UVOT Upper Limits"
}