{
  "version": 2,
  "bibcode": "2025GCN.41852....1S",
  "body": "R. Sonawane (IISER, TVM) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 06:27:44.33 UT on 17 September 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 250917B (trigger 779783269/250917269).\nwhich was also detected by Swift BAT (R. Caputo et al. 2025, GCN 41848).\nThe Fermi GBM on-ground location is consistent with the Swift BAT position.\n\nThe angle from the Fermi LAT boresight is 48 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 0.2 s (50-300 keV). The time-averaged spectrum\nfrom T0-0.2 to T0+0.3 s is best fit by\na power law function with an exponential high-energy cutoff.\nThe power law index is -1 +/- 0.2 and the cutoff energy,\nparameterized as Epeak, is 120 +/- 20 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(3.2 +/- 0.3)E-07 erg/cm^2. The 64-ms peak photon flux measured\nstarting from T0+0.0 s in the 10-1000 keV band is 24 +/- 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": 1758135187457,
  "submitter": "Rushikesh Digambar Sonawane PHD231014 at IISER, TVM <rushikesh23@iisertvm.ac.in>",
  "format": "text/plain",
  "subject": "GRB 250917B: Fermi GBM Observation",
  "submittedHow": "email",
  "editedOn": 1758136897737,
  "eventId": "GRB 250917B",
  "circularId": 41852,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Rushikesh sonawane at IISER, TVM <sonawanerushikesh521@gmail.com>"
}