{
  "body": "O.J. Roberts (USRA/NASA-MSFC) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 04:01:35.21 UT on 09 January 2024, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 240109A (trigger 726465700/240109168).\nwhich was also detected by Swift-BAT (S. Dichiara et al. 2024, GCN 35501).\nThe Fermi GBM on-ground Localization is consistent with the Swift-BAT position.\n\nThe angle from the Fermi LAT boresight is 79 degrees using the Swift-BAT position.\n\nThe GBM light curve consists of a single peak with a duration (T90)\nof about 0.26 s (50-300 keV). The time-averaged spectrum\nfrom T0-0.12 to T0+0.12 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -1.0 +/- 0.3 and the cutoff energy,\nparameterized as Epeak, is 305 +/- 179 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.6 +/- 0.4)E-07 erg/cm^2. The 0.064-sec peak photon flux measured\nstarting from T0-0.064 s in the 10-1000 keV band is 6 +/- 1 ph/s/cm^2.\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/\"",
  "bibcode": "2024GCN.35519....1R",
  "circularId": 35519,
  "eventId": "GRB 240109A",
  "subject": "GRB 240109A: Fermi GBM Observation",
  "submitter": "Oliver J Roberts at USRA/NASA <oliver.roberts@nasa.gov>",
  "createdOn": 1705004932350,
  "submittedHow": "web"
}