{
  "circularId": 35755,
  "submittedHow": "web",
  "bibcode": "2024GCN.35755....1V",
  "createdOn": 1708305674631,
  "submitter": "Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>",
  "body": "P. Veres and C. Meegan (both UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 02:00:21.72 UT on 18 February 2024, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 240218A (trigger 729914426/240218084),\nwhich was also detected by Swift/BAT (Page et al. 2024, GCN 35742). \nThe Fermi GBM on-ground localization is consistent with the Swift BAT position.\n\n\nThe angle from the Fermi LAT boresight is 93 degrees.\n\nThe GBM light curve consists of a single pulse followed by weaker emission with a duration (T90)\nof about 38 s (50-300 keV). The time-averaged spectrum\nfrom T0-2.6 to T0+30.2 s is best fit by\na Band function with Epeak = 100 +/- 20 keV,\nalpha = -0.3 +/- 0.3, and beta = -1.9 +/- 0.1.\n\nThe event fluence (10-1000 keV) in this time interval is\n(5.2 +/- 0.4)E-06 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+1.5 s in the 10-1000 keV band is 3.1 +/- 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:\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/\"",
  "eventId": "GRB 240218A",
  "subject": "GRB 240218A: Fermi GBM Detection"
}