{
  "bibcode": "2016GCN.19267....1S",
  "body": "M. H. Siegel (PSU) and P. A. Evans (U Leicester)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 160408A\n98 s after the BAT trigger (Evans et al., GCN Circ. 19260).\nNo optical afterglow consistent with the XRT position\n(Osborne et al. GCN Circ. 19261) or the possible\noptical counterparts (Levan et al., GCN Circ. 19262)\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            98          248          147         >21.0\nu_FC               311          561          246         >19.7\nwhite               98         1365          373         >21.8\nv                  641         1414           97         >19.4\nb                  566         1340           78         >19.6\nu                  311         1316          304         >19.9\nw1                 691         1291           58         >19.5\nm2                 838         1092           39         >18.8\nw2                 617         1390           97         >19.9\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": 19267,
  "createdOn": 1460146545000,
  "email": "siegel@swift.psu.edu",
  "subject": "GRB 160408A: Swift/UVOT Upper Limits",
  "submitter": "Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>",
  "eventId": "GRB 160408A"
}