{
  "bibcode": "2021GCN.30482....1S",
  "body": "M. H. Siegel (PSU) and P. D'Avanzo (INAF-OAB)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 210722A\n94 s after the BAT trigger (D'Avanzo et al., GCN Circ. 30475).\nA source consistent with the XRT position is detected in the initial UVOT exposures.\n\nThe preliminary UVOT position is:\n  RA  (J2000) =  01:48:07.28 =  27.03033 (deg.)\n  Dec (J2000) = -06:20:49.7  =  -6.34713 (deg.)\nwith an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).\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               94          244          147         14.31 +/- 0.02\nv                  637          656           19         14.52 +/- 0.06\nb                  563          583           20         14.65 +/- 0.04\nu                  308          557          246         13.68 +/- 0.02\nw1                 686          705           20         14.08 +/- 0.06\nw2                4908         4971           62         17.08 +/- 0.14\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.027 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 30482,
  "createdOn": 1627047971000,
  "email": "mhs18@psu.edu",
  "subject": "GRB 210722A: Swift/UVOT Detection",
  "submitter": "Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>",
  "eventId": "GRB 210722A"
}