{
  "bibcode": "2012GCN.13516....1H",
  "body": "S. T. Holland (STScI) and P. D'Avanzo (INAF-OAB)\nreport on behalf of the Swift/UVOT team:\n\n    The Swift/UVOT observed the field of GRB 120724A starting 99 s\nafter the BAT trigger (D'Avanzo et al., 2012, GCNC 13510).  Settled\nobservations started at 120 s.  We detect a faint source with preliminary\ncoordinates\n\n    RA (J2000)  16:20:43.35  =  245.18062 (deg)\n   Dec (J2000) +03:30:27.8   =   +3.50772 (deg)\n\nand an estimated uncertainty of 0.77 arcsec (radius, 90% confidence,\nstatistical + systematic).  This position is consistent with the\noptical source discovered by Guidorzi et al. (2012, GCNC 13511) and is\nslightly outside the UVOT-enhanced XRT position (D'Avanzo et al.,\n2012, GCNC 13514).  Preliminary magnitiudes for this source, and\n3-sigma upper limits for the finding charts (FC) and the co-added\nimages, are\n\nFilter       TSTART       TSTOP  EXPOSURE       Mag   Err  Sigma\n----------------------------------------------------------------\nwhite (FC)      117         267       147     >21.3\n   u (FC)      330         580       246     >20.5\nwhite (FC)      609         629        20     >19.8\n----------------------------------------------------------------\n  v            832        1404        72     >19.2\n  b            585        1331        58      20.01 0.41    2.7\n  u            330        1461       288      20.50 0.37    3.0\nuvw1           1088        1453        59     >19.2\nuvm2           1237        1429        39     >18.4\nuvw2            635        1380        78     >19.5\nwhite           117        1355       199      21.54 0.45    2.5\n----------------------------------------------------------------\n\n   The quoted magnitudes and upper limits have not been corrected for\nthe Galactic extinction along the line of sight to this burst of\nE_{B-V} = 0.05 mag (Schlafly et al. 2011, ApJS, 737, 103).",
  "circularId": 13516,
  "createdOn": 1343221902000,
  "email": "sholland@stsci.edu",
  "subject": "GRB 120724A: Swift/UVOT Detection of the Optical Afterglow",
  "submitter": "Stephen Holland at STScI  <sholland@stsci.edu>",
  "eventId": "GRB 120724A"
}