{
  "bibcode": "2012GCN.14092....1O",
  "body": "S. R. Oates (MSSL-UCL) and M. H. Siegel (PSU)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 121217A\n73 s after the BAT trigger (Siegel et al., GCN Circ. 14089).\nA source consistent with the GROND optical position (Elliott et al. GCN Circ. 14091)\nis detected in the initial UVOT exposures. The preliminary UVOT position is: \n\n    RA (J2000) = 10:14:50.32 = 153.7097  (deg)\n   Dec (J2000) = -62:21:03.3 = -62.35096 (deg)\n\nwith an estimated uncertainty of 0.6 arcsec (radius, 90% confidence).\n\nPreliminary detections and 3-sigma upper limits using the UVOT photometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: \n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\n\nwhite               73          222          147         19.58 +/- 0.13\nv                  616         5906          313         19.01 +/- 0.22\nb                  541          560          19          18.76 +/- 0.36\nu                  285         6522          540         20.09 +/- 0.34\nw1                 666         6317          313        >19.96\nm2                 641         6112          313        >19.85\nw2                 591         7138          510        >20.37\n\nThe magnitudes in the table are not corrected for the significant Galactic extinction\ndue to the reddening of E(B-V) = 0.37 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 14092,
  "createdOn": 1355768086000,
  "email": "sro@mssl.ucl.ac.uk",
  "subject": "GRB 121217A: Swift/UVOT Detection",
  "submitter": "Samantha Oates at MSSL  <sro@mssl.ucl.ac.uk>",
  "eventId": "GRB 121217A"
}