{
  "bibcode": "2018GCN.22565....1E",
  "body": "S.W.K. Emery (UCL-MSSL) and J. L. Racusin (NASA/GSFC)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 180329B\n113 s after the BAT trigger (Racusin et al., GCN Circ. 22558).\nA fading source consistent with the XRT position\n(Beardmore et al. GCN Circ. 22559) also detected by the\nNOT (Perley et al. GCN Circ. 22562) and RATIR (Watson et al. GCN Circ. 22564)\nis detected in the initial UVOT exposures.\n\nThe preliminary UVOT position is:\n    RA  (J2000) =  05:31:36.91 =  82.90381 (deg.)\n    Dec (J2000) = -23:41:25.8  = -23.69051 (deg.)\nwith an estimated uncertainty of 0.43 arc sec. (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              113          263          147         17.69 +/- 0.04\nwhite              550         6892          599         17.64 +/- 0.03\nv                  601         5867          274         17.25 +/- 0.07\nb                  526         6687          452         17.94 +/- 0.05\nu                  271         6482          697         17.00 +/- 0.04\nu                16039        39219         1961         18.74 +/- 0.07\nw1                 650         6277          452         18.72 +/- 0.14\nm2                 626         6073          274        >19.8\nw2                 577         7017          390        >20.2\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": 22565,
  "createdOn": 1522409894000,
  "email": "samuel.emery.15@ucl.ac.uk",
  "subject": "GRB 180329B: Swift/UVOT Detection",
  "submitter": "Sam Emery at MSSL-UCL  <samuel.emery.15@ucl.ac.uk>",
  "eventId": "GRB 180329B"
}