{
  "circularId": 37772,
  "eventId": "GRB 241009A",
  "subject": "GRB 241009A: Swift-XRT afterglow detection",
  "body": "M. A. Williams (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P.\nOsborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.\nLeicester), C. Salvaggio (INAF-OAB), M. Ferro (INAF-OAB), R. Brivio\n(INAF-OAB) and P.A. Evans (U. Leicester) reports on behalf of the\nSwift-XRT team:\n\nSwift-XRT has performed follow-up observations of the\nSVOM/ECLAIRs-detected burst GRB 241009A, collecting 2.1 ks of Photon\nCounting (PC) mode data between T0+14.7 ks and T0+106.0 ks. \n\nSeven uncatalogued X-ray sources are detected, of which one (\"Source\n1\") is believed to be the afterglow. Using 433 s of PC mode data and 1\nUVOT image, we find an enhanced XRT position (using the XRT-UVOT\nalignment and matching UVOT field sources to the USNO-B1 catalogue):\nRA, Dec = 325.00866, -35.65944 which is equivalent to:\n\nRA (J2000): 21h 40m 02.08s\nDec(J2000): -35d 39' 34.0\"\n\nwith an uncertainty of 4.2 arcsec (radius, 90% confidence). This\nposition is 6.3 arcmin from the SVOM/ECLAIRs position. The source has\nfaded from a count rate of 0.0441 [+0.013, -0.011] ct s^-1 at T0+14.9\nks to an upper limit of 0.0132 ct s^-1 at T0+100.9 ks.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00021722.\nThe results of the full analysis of the XRT observations are available\nat https://www.swift.ac.uk/ToO_GRBs/00021722.\n\nThis circular is an official product of the Swift-XRT team.\n\n",
  "bibcode": "2024GCN.37772....1W",
  "createdOn": 1728661660796,
  "submitter": "Phil Evans at U of Leicester <pae9@star.le.ac.uk>",
  "submittedHow": "email"
}