{
  "bibcode": "2008GCN..7643....1B",
  "body": "A.P. Beardmore (U. Leicester) and H. Ziaeepour (UCL-MSSL) report on behalf\nof the Swift-XRT team :\n\nThe Swift-XRT began observing GRB 080426 (trigger=310219, Ziaeepour et\nal.  GCN Circ. 7639) in Photon Counting mode, 230 s after the BAT\ntrigger.  The best XRT position for this burst is the UVOT-enhanced\nposition reported by Beardmore et al. (GCN Circ. 7641).\n\nThree orbits of data out to T+13 ks, totalling 5.7 ks of exposure,\nreveal a light curve which follows a simple power-law decay, with an\nindex of -1.07 +/- 0.08.\n\nThe spectrum from the first three orbits is well fit by an absorbed\npower-law model, with a photon index of 2.01 +/- 0.25 and column density\nof (5.3 +/- 1.3)e21 cm^-2, which is slightly in excess of the average\nGalactic column density in this direction of 3.7e21 cm^-2. The\nobserved (unabsorbed) 0.3-10 keV flux is 5.1e-12 (9.1e-12)\nerg cm^-2 s^-1.\n\nIf the burst continues to decay at the same rate, we predict an\nXRT count rate of 2.0e-3 count/s at T+24 hours, which corresponds\nto an observed 0.3-10 keV flux of approximately 1.2e-13 erg cm^-2 s^-1.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 7643,
  "createdOn": 1209247402000,
  "email": "apb@star.le.ac.uk",
  "subject": "GRB 080426: Swift-XRT refined analysis",
  "submitter": "Andy Beardmore at U Leicester  <apb@star.le.ac.uk>",
  "eventId": "GRB 080426"
}