{
  "bibcode": "2017GCN.20484....1B",
  "body": "A. A. Breeveld (UCL-MSSL) and A. Melandri (INAF-OAB)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 170117A\n86251 s after the BAT trigger (Palmer, GCN Circ. 20480).\nNo optical afterglow consistent with the BAT position given in that \ncircular is detected in the initial UVOT exposures.\nThe preliminary 3-sigma upper limit using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial summed \nexposures is:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite            86251       116034         2654         >22.0\n\nThe magnitudes in the table are not corrected for the Galactic \nextinction due to the reddening of E(B-V) = 0.35 in the direction of the \nburst (Schlegel et al. 1998).",
  "circularId": 20484,
  "createdOn": 1484829482000,
  "email": "a.breeveld@ucl.ac.uk",
  "subject": "GRB 170117A: Swift/UVOT Upper Limits",
  "submitter": "Alice Breeveld at MSSL-UCL  <a.breeveld@ucl.ac.uk>",
  "eventId": "GRB 170117A"
}