{
  "body": "A.A. Breeveld (UCL-MSSL) and A. Mei (INAF-OAB) report on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 251112A 304 s after the BAT trigger (Mei et al., GCN Circ. 42656).\nNo optical afterglow consistent with the XRT position (Lanava et al., GCN Circ. 42665) is detected in the initial UVOT exposures.\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\nu_FC               304          553          246         >19.9\nwhite              856          944           86         >20.0\nuvw1               683          697           14         >17.2\nuvm2               658          849           39         >17.6\nuvw2               609          801           39         >18.0\n\nThe magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.158 in the direction of the burst (Schlegel et al. 1998).\n",
  "createdOn": 1763043819937,
  "circularId": 42667,
  "submitter": "Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>",
  "submittedHow": "email",
  "eventId": "GRB 251112A",
  "subject": "GRB 251112A: Swift/UVOT Upper Limits",
  "bibcode": "2025GCN.42667....1B"
}