{
  "bibcode": "2018GCN.22893....1E",
  "body": "S.W.K. Emery (UCL-MSSL) and E. Sonbas (Adiyaman Univ.) and\nA. A. Breeveld (UCL-MSSL)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 180704A\n3255 s after the BAT trigger (Sonbas et al., GCN Circ. 22885).\nNo optical afterglow consistent with the XRT position\n(Evans et al. GCN Circ. 22890)\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 first\nexposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite             3255         5455          537         >20.8\nv                 4233        10567         1082         >19.8\nb                 3618         5253          393         >19.9\nu                 3413         5048          393         >19.6\nuvw1                4643         4843          197         >19.2\nuvm2                4438        11190          804         >20.3\nuvw2                4028         9654         1082         >20.7\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.87 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 22893,
  "createdOn": 1530711103000,
  "email": "samuel.emery.15@ucl.ac.uk",
  "subject": "GRB 180704A: Swift/UVOT Upper Limits",
  "submitter": "Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>",
  "eventId": "GRB 180704A"
}