{
  "subject": "GRB 091020: Fermi GBM observation",
  "eventId": "GRB 091020",
  "bibcode": "2009GCN.10095....1C",
  "createdOn": 1256740037000,
  "circularId": 10095,
  "submitter": "Vandiver Chaplin at UAH/Fermi-GBM  <chapliv@email.uah.edu>",
  "email": "chapliv@email.uah.edu",
  "body": "V.Chaplin (UAH) reports on behalf of the Fermi GBM Team:\n\n\"At 21:36:43.82 UT on 20 October 2009, the Fermi\nGamma-Ray Burst Monitor triggered on GRB 091020\n(trigger 277767405 / 091020900), which was also detected by\nthe Swift-BAT (Racusin et al., GCN 10048).\nThe angle from the Fermi LAT boresight of the Swift-XRT position\n(Beardmore et al., GCN 10050) is 118 degrees.\n\nThe GBM light curve consists of a single pulse\nwith a duration (T90) of about 37 s (8-1000 keV).\nThe time-averaged spectrum from T0-7.7 s to T0+21 s is\nbest fit by a Band function with Epeak = 47.9 +/- 7.1 keV,\nalpha = 0.2 +/- 0.4, and beta = -1.7 +/- .02.\n\nThe event fluence (8-1000 keV) in this time interval is\n(1.0 +/- 0.2)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+1.5 s in the 8-1000 keV band\nis 7.4 +/- 0.5 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\""
}