{
  "bibcode": "2023GCN.33288....1P",
  "body": "S. Poolakkil (UAH) and C. Meegan (UAH)\nreport on behalf of the Fermi GBM Team:\n\n\"At 21:44:27.20 UT on 4 February 2023, the Fermi Gamma-Ray Burst Monitor\n(GBM)\ntriggered and located GRB 230204B (trigger 697239872 / 230204906)\nwhich was also detected by the Swift/BAT-GUANO (Kennea et al. 2023, GCN\n33267),\nSwift-XRT (D'Elia et al. 2023, GCN 33285), MAXI/GS (Serino et al. 2023, GCN\n33265),\nAGILE (Casentini et al. 2023, GCN 33272), ATLAS (Smartt et al. 2023, GCN\n33278),\nand VLT/X-shooter (Saccardi et al. 2023, GCN 33281).\n\nThe angle from the Fermi LAT boresight at the GBM trigger time is 106\ndegrees.\n\nThe GBM light curve consists of multiple peaks followed\nby some extended emission with a duration (T90) of about 216 s (50-300 keV).\nThe time-averaged spectrum from T0-1.024 s to T0+228.4 s\nis best fit by a power law function with an exponential\nhigh-energy cutoff. The power law index is -0.97 +/- 0.02  and\nthe cutoff energy, parameterized as Epeak, is 783 +/- 40 keV.\nA Band function fits equally well, with Epeak = 763 +/- 45 keV,\nalpha = -0.97 +/- 0.02 and beta = -2.73 +/- 0.29.\n\nThe event fluence (10-1000 keV) in this time interval is\n(138.9 +/- 1.5)E-06 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+156 s in the 10-1000 keV band\nis 7.3 +/- 0.4 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\nPage:\nhttps://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "circularId": 33288,
  "createdOn": 1675715298000,
  "email": "sp0076@uah.edu",
  "subject": "GRB 230204B: Fermi GBM detection",
  "submitter": "Suraj Poolakkil at UAH  <sp0076@uah.edu>",
  "eventId": "GRB 230204B"
}