{
  "bibcode": "2015GCN.17511....1C",
  "body": "Valerie Connaughton and Peter Jenke (UAH) and Adam Goldstein (NASA MSFC)\nreport on behalf of the Fermi GBM Team:\n\n\"At 01:04:28.65 UT on 01 March 2015, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 150301A (trigger 446864671 / 150301045)\nwhich was also detected by the Swift/BAT (Lien et al. 2015, GCN 17510).\nThe GBM on-ground location is consistent with the Swift position.\n\nThe angle from the Fermi LAT boresight is 105 degrees.\n\nThe GBM light curve consists of a single peak about 50 ms in duration.\nThe counts registered in the NaI detectors are strongly peaked in the\n50 - 300 keV energy range typical for GRBs.  From the quicklook\ndata, the softness ratio for the event (20 - 100 keV / 100 - 500 keV)\nis 0.4 +/- 0.3, typical for fairly hard GRBs.  By contrast,\nthe corresponding softness ratios for recent triggers from\nSGR 1935+2154 and AXP 4U 0142+61 were\n4.4 +/- 1.8, 3.4 +/- 1.0, and 2.2 +/- 0.4.\n\nThe time-averaged spectrum from T0-0.016 s to T0+0.032 s is\nbest fit by a power law function with an exponential\nhigh-energy cutoff.  The power law index is -0.53 +/- 0.35 and\nthe cutoff energy, parameterized as Epeak, is 185 +/- 49 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.2 +/- 0.2)E-07 erg/cm^2. The 16-msec peak photon flux measured\nstarting from T0-0.016 s in the 10-1000 keV band\nis 29 +/- 4 ph/s/cm^2.\n\nThe spectral characteristics of this burst are more like a GRB than\nan SGR.  We think it is therefore unlikely that this event is a burst\nfrom a new SGR and conclude that it is, instead, a short GRB.\n\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 17511,
  "createdOn": 1425187553000,
  "email": "valerie.connaughton@nasa.gov",
  "subject": "GRB 150301A: Fermi GBM observation",
  "submitter": "Valerie Connaughton at UAH/NSSTC  <valerie.connaughton@nasa.gov>",
  "eventId": "GRB 150301A"
}