{
  "createdOn": 1753941437789,
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>",
  "body": "K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), T. Sbarrato\n(INAF-OAB), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), S.\nDichiara (PSU), J.A. Kennea (PSU), D.N. Burrows (PSU) and P.A. Evans\n(U. Leicester) reports on behalf of the Swift-XRT team:\n\nWe have analysed 5.9 ks of XRT data for GRB 250727A, from 2.4 ks to\n300.7 ks after the  SVOM/ECLAIRs trigger. The data are entirely in\nPhoton Counting (PC) mode. During this second observation, source 1\n(SWIFT J234539.1-811248) given in GCN Circ. 41180 is found to have\nfaded at the 3.7-sigma level, so we believe this to be the X-ray\nafterglow. We also note that EP-FXT found this source to have faded\n(GCN Circ. 41199).\n\nUsing 1353 s of PC mode data and 1 UVOT image, we find an enhanced XRT\nposition (using the XRT-UVOT alignment and matching UVOT field sources\nto the USNO-B1 catalogue): RA, Dec = 356.41475, -81.21390 which is\nequivalent to:\n\nRA (J2000): 23h 45m 39.54s\nDec(J2000): -81d 12' 50.1\"\n\nwith an uncertainty of 4.3 arcsec (radius, 90% confidence). The source\nis fading with alpha >0.3.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00019965.\n\nThis circular is an official product of the Swift-XRT team.\n\n",
  "eventId": "GRB 250727A",
  "submittedHow": "email",
  "bibcode": "2025GCN.41208....1P",
  "subject": "GRB 250727A: Swift-XRT afterglow confirmation and refined analysis",
  "circularId": 41208
}