{
  "circularId": 45976,
  "eventType": [
    "GRB",
    "Gamma-ray Transient"
  ],
  "eventId": "GRB 261017A",
  "submitter": "oindabimukherjee@gmail.com",
  "submittedHow": "web",
  "subject": "GRB 261017A: Fermi GBM Observation",
  "body": "O. Mukherjee (USRA), L. Scotton (UAH) and P. Veres (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 16:05:05.10 UT on 17 October 2026, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 261017A (trigger 813945910/261017670),\nwhich was also detected by Swift BAT (M. H. Siegel et al. 2026, GCN 45974).\nThe Fermi GBM on-ground location is consistent with the Swift BAT position.\n\nThe angle from the Fermi LAT boresight is 67 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 9.2 s (50-300 keV). The time-averaged spectrum\nfrom T0-0.6 to T0+10 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -0.44 +/- 0.01 and the cutoff energy,\nparameterized as Epeak, is 1024 +/- 22 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.22 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+0.26 s in the 10-1000 keV band is 4.3 +/- 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/\"",
  "createdOn": 1792284706947,
  "format": "text/plain"
}