{
  "bibcode": "2011GCN.12221....1G",
  "body": "David Gruber (MPE) reports on behalf of the Fermi GBM Team: \n\n\"At 11:09:29.94 UT on 31 July 2011, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 110731A (trigger 333803371 / 110731465)\nwhich which was also detected by Fermi LAT (Bregeon et al. 2011, GCN 12218)\nand Swift (Oates et al. 2011, GCN 12215).\n\nThe GBM on-ground location is consistent with the Swift position.\nThe angle from the Fermi LAT boresight is 6 degrees.\nMoreover, this burst was bright enough to result in a Fermi spacecraft \nautonomous rapid repoint (ARR) maneuver.\n\nThe GBM light curve consists of one pulse\nwith a duration (T90) of about 7.3 +/- 0.3 s (50-300 keV). \nThe time-averaged spectrum from T0 s to T0+7.3 s is \nbest fit by a power law function with an exponential\nhigh-energy cutoff.  The power law index is -0.82 +/- 0.03 and\nthe cutoff energy, parameterized as Epeak, is 317 +/- 10 keV.\n\nThe event fluence (10-1000 keV) in this time interval is \n(2.218 +/- 0.006)E-05 erg/cm^2. The 1-sec peak photon flux measured \nstarting from T0+0.128 s in the 10-1000 keV band \nis 20.9 +/- 0.5 ph/s/cm^2.\n\nA Band function fits the spectrum equally well \nwith Epeak= 304 +/- 13 keV, alpha = -0.80 +/- 0.03 and beta = -2.98 +/- 0.30. \n\n\nThe spectral analysis results presented above are preliminary; \nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 12221,
  "createdOn": 1312180178000,
  "email": "dgruber@mpe.mpg.de",
  "subject": "GRB 110731A: Fermi GBM observation",
  "submitter": "David Gruber at MPE  <dgruber@mpe.mpg.de>",
  "eventId": "GRB 110731A"
}