{
  "bibcode": "2016GCN.20282....1M",
  "body": "F. E. Marshall (NASA/GSFC) and V. D'Elia (ASDC)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 161217A\n163 s after the BAT trigger (D'Elia et al., GCN Circ. 20276).\nNo optical afterglow consistent with the enhanced XRT position\n(Osborne et al., GCN Circ. 20278)\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) exposures and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\n\nwhite_FC           163          308          142         >21.0\nu_FC               314          564          246         >21.0\nwhite              163         1713          406         >21.2\nv                  644         1589          117         >18.8\nb                  576         1689          111         >19.8\nu                  314         1664          343         >20.4\nw1                 693         1639           97         >20.3\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.01 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 20282,
  "createdOn": 1481995614000,
  "email": "femarsha@khamseen.gsfc.nasa.gov",
  "subject": "GRB 161217A: Swift/UVOT Upper Limits",
  "submitter": "Frank Marshall at GSFC  <femarsha@khamseen.gsfc.nasa.gov>",
  "eventId": "GRB 161217A"
}