{
  "bibcode": "2009GCN.10187....1G",
  "body": "David Gruber (MPE) reports on behalf of the Fermi GBM Team: \n\n\n\"At 04:34:40.23  UT on 20 November 2009, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 091120 (trigger 280384482 / 091120191).\n\nThe on-ground calculated location, using the GBM trigger \ndata, is RA = 224.8, DEC = -24.8 (J2000 degrees, \nequivalent to 14h 59m, -24d 48'), with an uncertainty \nof 1.32 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 45 degrees.\nMoreover, this burst was bright enough to result in\na Fermi spacecraft repointing maneuver.\n\nThe GBM light curve consists of several peaks with a \nduration (T90) of about 52 s (8-1000 keV). \nThe time-averaged spectrum from T0-3 s to T0+56 s is \nadequately fit by a power law function with an exponential\nhigh energy cutoff.  The power law index is -1.17 +/- 0.02 and\nthe cutoff energy, parameterized as Epeak, is 129 +/- 3 keV.\n(C-stat 691 for 362 d.o.f.).\n\nThe event fluence (8-1000 keV) in this time interval is \n(3.02 +/- 0.04)E-5 erg/cm^2. The 1-sec peak photon flux measured \nstarting from T0+26.6 s in the 8-1000 keV band \nis 21.3 +/- 0.4 ph/s/cm^2.\n\nA Band function fits the spectrum equally well (C-stat 687 for 361 d.o.f.) \nwith Epeak= 124 +/- 4 keV, alpha = -1.15 +/- 0.02 \nand beta = -2.98 +/- 0.27. \n\nThe spectral analysis results presented above are preliminary; \nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 10187,
  "createdOn": 1259057678000,
  "email": "dgruber@mpe.mpg.de",
  "subject": "GRB 091120: Fermi GBM observation",
  "submitter": "David Gruber at MPE  <dgruber@mpe.mpg.de>",
  "eventId": "GRB 091120"
}