{
  "bibcode": "2012GCN.12796....1B",
  "body": "A. A. Breeveld (MSSL-UCL) and F. E. Marshall (NASA/GSFC)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 120102A\n121 s after the BAT trigger (Marshall et al., GCN Circ. 12794).\nA fading source consistent with the XRT position (Beardmore et al., GCN \nCirc. 12795) is detected in the initial UVOT exposures.\n\nThe preliminary UVOT position is:\n     RA  (J2000) =  18:24:53.89 = 276.22456 (deg.)\n     Dec (J2000) = +24:42:47.1  =  24.71309 (deg.)\nwith an estimated uncertainty of 0.51 arc sec. (radius, 90% confidence).\n\nPreliminary detections and 3-sigma upper limits using the UVOT \nphotometric system\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the finding chart \n(FC) and early exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\n\nwhite (FC)         121          271          147         18.10 � 0.06\nwhite              788         1014          167         19.9  � 0.2\nv                  663         1239           78         18.16 � 0.31\nb                  589        11310         1147        >20.8\nu                  334          583          246         18.52 � 0.14\nw1                 713         6983          452        >20.2\nm2                 688         6778          452        >20.1\nw2                 639        12879         1112        >20.9\n\nThe magnitudes in the table are not corrected for the Galactic \nextinction due to the reddening of E(B-V) = 0.13 in the direction of the \nburst (Schlegel et al. 1998).",
  "circularId": 12796,
  "createdOn": 1325508087000,
  "email": "aab@mssl.ucl.ac.uk",
  "subject": "GRB 120102A: Swift/UVOT Detection",
  "submitter": "Alice Breeveld at MSSL-UCL  <aab@mssl.ucl.ac.uk>",
  "eventId": "GRB 120102A"
}