{
  "circularId": 35444,
  "bibcode": "2023GCN.35444....1F",
  "eventId": "GRB 231230A",
  "createdOn": 1703961614902,
  "submittedHow": "web",
  "subject": "GRB231230A: Fermi GBM Observation",
  "body": "C. Fletcher (USRA) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 01:29:10.05 UT on 30 December 2023, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB231230A (trigger 725592555/231230062).\nwhich was also detected by Swift-BAT (Moss et al. 2023, GCN 35436).\nThe Fermi GBM Real-time Localization (GCN 35434) is consistent with the Swift-BAT position.\n\nThe angle from the Fermi LAT boresight is 157 degrees.\n\nThe GBM light curve consists of multiple spikes with a duration (T90)\nof about 17 s (50-300 keV). The time-averaged spectrum\nfrom T0-2.6 to T0+17.9 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -1.2 +/- 0.2 and the cutoff energy,\nparameterized as Epeak, is 220 +/- 40 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(6.1 +/- 0.5)E-06 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+9.3 s in the 10-1000 keV band is 5 +/- 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/\"",
  "submitter": "Cori Fletcher at USRA <cfletcher@usra.edu>"
}