{
  "bibcode": "2021GCN.29697....1L",
  "body": "GRB 210321A: Swift/UVOT Detection\n\nS. J. Laporte (PSU) and S. Dichiara (NASA/GSFC/UMCP)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 210321A\n2735 s after the BAT trigger (Dichiara et al., GCN Circ. 29677).\nA source consistent with the XRT position\n(Beardmore et al. GCN Circ. 29681)\nis detected in the initial UVOT exposures.\n\nThe preliminary UVOT position is:\n    RA  (J2000) =  05:51:34.75 =  87.89479 (deg.)\n    Dec (J2000) = +70:07:49.8  =  70.13051 (deg.)\nwith an estimated uncertainty of 0.49 arc sec. (radius, 90% confidence).\n\nPreliminary detections and 3-sigma upper limits using the UVOT photometric\nsystem\n(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures\nare:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)           Mag\n\nwhite             2735         2885          147         18.69 +/- 0.09\nv                 2892         4465          331         18.44 +/- 0.16\nb                 3713         3913          197         18.64 +/- 0.11\nu                 3507         3706          197         18.29 +/- 0.12\nw1                3302         3502          197         18.48 +/- 0.17\nm2                3097         3296          197        >18.9\nw2                4124         4324          197        >19.8\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.118 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 29697,
  "createdOn": 1616509079000,
  "email": "sjl5346@psu.edu",
  "subject": "GRB 210321A: Swift/UVOT Detection",
  "submitter": "Sam LaPorte at PSU  <sjl5346@psu.edu>",
  "eventId": "GRB 210321A"
}