{
  "bibcode": "2021GCN.29559....1S",
  "body": "M. H. Siegel (PSU) and J. D. Gropp (PSU)\nreport on behalf of the Swift/UVOT team:\n\nThe Swift/UVOT began settled observations of the field of GRB 210222B\n101 s after the BAT trigger (Gropp et al., GCN Circ. 29545).\nA source consistent with the XRT position (Gropp et al. GCN Circ. 29545)\nis detected in the initial UVOT exposures. This source is also consistent\nwith previously reported optical detections (Hu et al., GCN Circ. 29546; \nStrausbaugh, GCN Circ. 29547; Mong et al., GCN Circ. 29548; Parley, GCN Circ.\n29549; Zhu et al., GCN Circ. 29551, Lipunov et al., GCN Circ. 29554). We note\nthat the lack of detection in the NUV passbands would be consistent with the\nredshift of 2.198 reported by Agui Fernandez et al. (GCN Circ. 29552).\n\nThe preliminary UVOT position is:\n   RA  (J2000) =  10:18:25.43 = 154.60595 (deg.)\n   Dec (J2000) = -14:55:55.1  = -14.93198 (deg.)\nwith an estimated uncertainty of 0.42 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              101          250          147         16.89 +/- 0.03\nv                  588          608           19         16.80 +/- 0.17\nb                  515          534           20         17.24 +/- 0.12\nu                  259          508          246         16.82 +/- 0.04\nw1                 639         1793          124        >18.8\nm2                 614         1606           78        >20.1\nw2                 564         1732          136        >19.1\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.102 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 29559,
  "createdOn": 1614106659000,
  "email": "mhs18@psu.edu",
  "subject": "GRB 210222B: Swift/UVOT Detection",
  "submitter": "Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>",
  "eventId": "GRB 210222B"
}