{
  "bibcode": "2009GCN..8822....1C",
  "body": "Valerie Connaughton (UAH) reports on behalf of the Fermi GBM Team:\n\n\"At 15:10:40.18 UT on 17 Jan 2009, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 090117C (trigger 253897842 / 090117632).\n\nThe on-ground calculated location, using the GBM trigger\ndata, is RA = 117.6, DEC = -40.3 (J2000 degrees,\nequivalent to 07h 50m, -40d 18'), with an uncertainty\nof 1.8 degrees (radius, 1-sigma containment,\nstatistical only; there is additionally a systematic\nerror which is currently estimated to be 2 to 3 degrees).\n \nThe angle from the Fermi LAT boresight is 54 degrees.\n\nThe GBM light curve consists of a precursor lasting tens\nof seconds until trigger time, followed by a single episode with\nsubstructure lasting a further 35 s.  The total duration (T90)\nbetween 8 and 1000 keV is about 86 s.\n \nThe time-averaged spectrum of the main emission\nfrom T0-2 s to T0+29 s is best fit by a Band function with\nEpeak = 247 +/- 41 keV, alpha = -1.0 +/- 0.1, and\nbeta = -2.1 +/- 0.2, giving an 8-1000 keV fluence of\n(1.1 +/- 0.1) E-5 erg/cm^2.  \n\nThe precursor spectrum from T0-55 sec to T0-6 s is best fit\nusing a power law function with an exponential\nhigh energy cutoff.  The power law index is -1.3 +/- 0.1 and\nthe cutoff energy, parameterized as Epeak, is 147 +/- 38 keV.\nThe 8-1000 keV fluence of the precursor is\n(3.9 +/- 0.5) E-6 erg/cm^2.\n\nA 1-sec peak photon flux of 4.2 +/- 0.7 ph/s/cm^2\nin the 8-1000 keV band is measured starting at T0+22.5 s.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 8822,
  "createdOn": 1232259323000,
  "email": "valerie@nasa.gov",
  "subject": "GRB 090117C - Fermi GRB Detection",
  "submitter": "Valerie Connaughton at MSFC  <valerie@nasa.gov>",
  "eventId": "GRB 090117C"
}