{
  "circularId": 37239,
  "eventId": "GRB 240821A",
  "bibcode": "2024GCN.37239....1D",
  "body": "S. Dalessi (UAH) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 18:36:02.60 UT on 21 August 2024, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 240821A (trigger 745958167/240821775).\nwhich was also detected by SVOM (F. Cangemi et al. 2024 GCN 37220, J. He et al. 2024 37226) and EIRSAT-1 (D. Murphy et al. 2024, GCN 37232).\nThe Fermi GBM on-ground location is consistent with the SVOM position.\n\nThe angle from the Fermi LAT boresight is 89 degrees.\n\nThe GBM light curve single emission episode with a duration (T90)\nof about 1.9 s (50-300 keV). The time-averaged spectrum\nfrom T0-0.2 to T0+2.9 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -0.93 +/- 0.06 and the cutoff energy,\nparameterized as Epeak, is 370 +/- 40 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(3.9 +/- 0.2)E-06 erg/cm^2. The 64-ms peak photon flux measured\nstarting from T0+0.64 s in the 10-1000 keV band is 28 +/- 2 ph/s/cm^2.\n\nA Band function fits the spectrum equally well with Epeak= 238 +/- 42 keV, alpha = -0.74 +/- 0.11 and beta = -1.96 +/- 0.11.\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/\"",
  "submittedHow": "web",
  "createdOn": 1724360970855,
  "submitter": "Sarah Dalessi at UAH <sd0104@uah.edu>",
  "format": "text/plain",
  "subject": "GRB 240821A: Fermi GBM Observation"
}