{
  "bibcode": "2014GCN.15997....1P",
  "body": "B. Porterfield (PSU) and Cenko (GSFC)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 140318A\n132 s after the BAT trigger (Cenko et al., GCN Circ. 15986).\nNo optical afterglow consistent with the XRT position\n(Cenko et al. GCN Circ. 15986) or NOT position (Schulze et al., GCN \nCirc 15987) is 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           132          282          147         >21.2\nwhite              132         5340          541         >21.9\nv                 4115         5750          393         >19.6\nb                 3499         5135          393         >20.9\nu                 4730         4930          197         >20.1\nw1                4525         6063          298         >20.5\nm2                4320         5955          393         >21.2\nw2                3910         5546          393         >20.7\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.02 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 15997,
  "createdOn": 1395238058000,
  "email": "siegel@swift.psu.edu",
  "subject": "GRB 140318A: Swift/UVOT Upper Limits",
  "submitter": "Mike Siegel at PSU/Swift MOC  <siegel@swift.psu.edu>",
  "eventId": "GRB 140318A"
}