{
  "bibcode": "2017GCN.20441....1S",
  "body": "M.H. Siegel (PSU) and A. P. Beardmore (U Leicester) \nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 170111A\n111 s after the BAT trigger (Beardmore et al., GCN Circ. 20423).\nNo optical afterglow consistent with the XRT position\n(Evans et al., GCN Circ. 20424)\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\nfinding chart (FC) exposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite_FC           111          261          147         >20.6\nwhite              111          570          167         >20.7\nv                  601          621           19         >18.0\nb                  525          545           19         >19.6\nu                  676          696           19         >19.3\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.03 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 20441,
  "createdOn": 1484230879000,
  "email": "siegel@swift.psu.edu",
  "subject": "GRB 170111A: Swift/UVOT Upper Limits",
  "submitter": "Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>",
  "eventId": "GRB 170111A"
}