{
  "bibcode": "2017GCN.22239....1E",
  "body": "S.W.K. Emery (UCL-MSSL) and J. D. Gropp (PSU)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 171211A\n362 s after the BAT trigger (Gropp et al., GCN Circ. 22234).\nNo optical afterglow consistent with the XRT position\n(Beardmore et al. GCN Circ. 22236)\nis 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 initial exposures are:\n\nFilter           T_start(s)   T_stop(s)      Exp(s)         Mag\n\nv                    387         6321          491         >19.0\nuvw1                 436         6731          491         >19.7\nuvm2                5503         6526          393         >19.9\nuvw2                 362         6939          668         >20.2\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.11 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 22239,
  "createdOn": 1513011661000,
  "email": "samuel.emery.15@ucl.ac.uk",
  "subject": "GRB 171211A: Swift/UVOT Upper Limits",
  "submitter": "Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>",
  "eventId": "GRB 171211A"
}