{
  "bibcode": "2009GCN..9300....1B",
  "body": "A.J. van der Horst (NASA/MSFC/ORAU) reports on behalf of the\nFermi GBM Team:\n\n\"At 16:33:49.27 UT on 26 April 2009, the Fermi Gamma-ray Burst Monitor\n(GBM) triggered and located GRB 090426C (trigger 262456415 / 090426.690).\nThe on-ground calculated location, using the Fermi GBM trigger data,\nis RA = 82.7, Dec = -9.7 (J2000 degrees, equivalent to\nJ2000 5h31m, -9d40'), with a statistical uncertainty of 2.0 degrees\n(radius, 1-sigma containment, statistical only; there is additionally\na systematic error which is currently estimated to be 2 to 3 degrees).\nThe angle from the Fermi LAT boresight is 69 degrees.\n\nThe GBM light curve consists of one main pulse, with a duration of ~12\nseconds. The time-averaged spectrum from T0-0.4 to T0+9.9 s is adequately\nfit by a power law with an exponential high-energy cutoff, but can also\nbe well fit by a Band function, although the beta value for the latter\nis poorly constrained. For the power law with exponential cutoff, the\nindex is -1.31 +/- 0.09 and the cutoff energy, parameterized as Epeak,\nis 351 +150/-81 keV. For the Band function, alpha is -1.29 +/- 0.11,\nbeta is -1.98 +0.17/-0.64 and Epeak is 295 +166/-83.\nThe fluence (8-1000 keV) in this time interval is (3.1 +/- 0.2)E-6 \nerg/cm^2.\nThe 1-sec peak photon flux measured starting from T0+0.7s in the\n8-1000 keV band is 6.8 +/- 0.7 ph/s/cm^2.\n\nThe temporal and spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 9300,
  "createdOn": 1241036463000,
  "email": "Alexander.J.VanDerHorst@nasa.gov",
  "subject": "GRB 090426C: Fermi GBM detection",
  "submitter": "Alexander van der Horst at NASA/MSFC  <Alexander.J.VanDerHorst@nasa.gov>",
  "eventId": "GRB 090426C"
}