{
  "bibcode": "2016GCN.19308....1M",
  "body": "F. E. Marshall (NASA/GSFC) and S. L. Gibson (U. Leicester)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 160412A\n90 s after the BAT trigger (Gibson et al., GCN Circ. 19298).\nNo optical afterglow consistent with the enhanced XRT position\n(Goad et al. GCN Circ. 19299)\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            90          240          147         >20.4\nu_FC               303          552          246         >19.1\nwhite               90         1878          431         >21.1\nv                  633         2101          175         >19.3\nb                  558         2026          156         >19.7\nu                  303         2001          362         >19.5\nw1                 682         2150          156         >19.8\nm2                1063         2125           97         >19.2\nw2                 608         2076          175         >19.7\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.04 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 19308,
  "createdOn": 1460495379000,
  "email": "femarsha@khamseen.gsfc.nasa.gov",
  "subject": "GRB 160412A: Swift/UVOT Upper Limits",
  "submitter": "Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>",
  "eventId": "GRB 160412A"
}