{
  "bibcode": "2021GCN.30734....1G",
  "body": "J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester),\nJ.P. Osborne (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo\n(INAF-OAB), M.G. Bernardini (INAF-OAB), A. Tohuvavohu (U. Toronto) and\nP.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:\n\nSwift-XRT has performed follow-up observations of the\nSwift/BAT-GUANO-detected burst GRB 210827A (James DeLaunay et al. GCN\nCirc. 30732), collecting 2.3 ks of Photon Counting (PC) mode data\nbetween T0+44.4 ks and T0+50.4 ks. \n\nOne uncatalogued X-ray source has been detected consistent with being\nwithin 296 arcsec of the Swift/BAT-GUANO position, it is below the RASS\nlimit and shows no definitive signs of fading. Therefore, at the\npresent time we cannot confirm this as the afterglow. Details of this\nsource are given below:\n\nSource 3:\n  RA (J2000.0):  174.9003  =  11:39:36.07\n  Dec (J2000.0): +55.7239  =  +55:43:26.2\n  Error: 3.8 arcsec (radius, 90% conf. [Enhanced position])\n  Count-rate: 0.0103 +/- 0.0025 ct s^-1   \n  Distance: 225 arcsec from Swift/BAT-GUANO position.\n  Flux: (4.8 +/- 1.2)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)\n\nFour uncatalogued sources were also detected too far from the GRB\nposition to be likely afterglow candidates.\n\nThe results of the XRT-team automatic analysis of the XRT observations,\nincluding a position-specific upper limit calculator, are available at\nhttps://www.swift.ac.uk/ToO_GRBs/00021461.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 30734,
  "createdOn": 1630141116000,
  "email": "paolo.davanzo@inaf.it",
  "subject": "GRB 210827A: Swift-XRT observations",
  "submitter": "Paolo D'Avanzo at INAF - OAB  <paolo.davanzo@inaf.it>",
  "eventId": "GRB 210827A"
}