{
  "bibcode": "2019GCN.23666....1F",
  "body": "C. Fletcher (USRA) and C. Meegan (UAH)\nreport on behalf of the Fermi GBM Team:\n\n\"At 11:56:10.76 UT on 09 January 2019, the Fermi Gamma-Ray Burst Monitor\ntriggered and located GRB 190109B (trigger 568727775 / 190109497)\nwhich was also detected by the Swift (Sbarufatti et al. 2019, GCN 23648).\nThe GBM on-ground location is consistent with the Swift position.\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 46 degrees.\n\nThe GBM light curve consists of a single peak\nwith a duration (T90) of about 8 s (50-300 keV).\nThe time-averaged spectrum from T0-6.1 s to T0+3.1 s is\nbest fit by a power law function with an exponential\nhigh-energy cutoff.  The power law index is -0.85 +/- 0.25 and\nthe cutoff energy, parameterized as Epeak, is 92 +/- 14 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(6.76 +/- 0.67)E-7 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0-1.6 s in the 10-1000 keV band\nis 2.8 +/- 0.2 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog.\"",
  "circularId": 23666,
  "createdOn": 1547076649000,
  "email": "corinne.l.fletcher@nasa.gov",
  "subject": "GRB 190109B: Fermi GBM observation",
  "submitter": "Cori Fletcher at USRA/NASA  <corinne.l.fletcher@nasa.gov>",
  "eventId": "GRB 190109B"
}