{
  "bibcode": "2021GCN.29679....1S",
  "body": "M.. H. Siegel (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 (Perri et al., GCN Circ. 29678)\nis detected in the initial UVOT exposures.\n\nPreliminary detections 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             2735         2837          100         18.76 +/- 0.11\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.116 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 29679,
  "createdOn": 1616333749000,
  "email": "mhs18@psu.edu",
  "subject": "GRB 210321A: Swift/UVOT Detection",
  "submitter": "Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>",
  "eventId": "GRB 210321A"
}