{
  "bibcode": "2022GCN.31660....1W",
  "body": "J. Wood (NASA/MSFC) and C. Meegan (UAH)\nreport on behalf of the Fermi GBM Team:\n\n\"At 10:30:05.92 UT on 28 Feb 2022, the Fermi Gamma-Ray Burst Monitor (GBM)\ntriggered and located GRB 220228A (trigger 667737010 / 220228438)\nwhich was also detected by the Fermi LAT (N. Omodei et al. 2022, GCN 31659).\nThe GBM on-ground location (GCN 31658) is consistent with the LAT position.\n\nThe GBM light curve consists of a single pulse\nwith a duration (T90) of about 12.5 s (50-300 keV).\nThe time-averaged spectrum from T0-7 s to T0+6 s is\nbest fit by a power law function with an exponential\nhigh-energy cutoff.  The power law index is 1.7 +/- 0.2 and\nthe cutoff energy, parameterized as Epeak, is 106 +/- 46 keV\n\nThe event fluence (10-1000 keV) in this time interval is\n((1.1 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0-0.5 s in the 10-1000 keV band\nis 3.1 +/- 0.2 ph/s/cm^2.\n\nA power law function fits the spectrum equally well\nwith index -1.9 +/- 0.1.\n\nThe spectral analysis results presented above are preliminary;\nfinal results will be published in the GBM GRB Catalog:\nhttps://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html\n\nFor Fermi GBM data and info, please visit the official Fermi GBM Support Page:\nhttps://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "circularId": 31660,
  "createdOn": 1646087162000,
  "email": "joshua.r.wood@nasa.gov",
  "subject": "GRB 220228A: Fermi GBM observation",
  "submitter": "Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>",
  "eventId": "GRB 220228A"
}