{
  "body": "Eliza Neights (GWU, NASA GSFC) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 14:17:19.05 UT on 01 October 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 251001B (trigger 781021044/251001595)\nwhich was also detected by Swift BAT (A. P. Beardmore et al. 2025, GCN 42039).\nThe Fermi GBM on-ground location is consistent with the Swift BAT position.\n\nThe angle from the Fermi LAT boresight is 53 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 19 s (50-300 keV). The time-averaged spectrum\nfrom T0-3.7 to T0+16.7 s is best fit by\na Comptonized function with index 0.22 +/- 0.03 and peak energy 107 +/- 5 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.3 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+0.7 s in the 10-1000 keV band is 1.4 +/- 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/\"",
  "bibcode": "2025GCN.42047....1N",
  "circularId": 42047,
  "createdOn": 1759354398005,
  "submittedHow": "web",
  "submitter": "eliza.neights@gmail.com",
  "subject": "GRB 251001B: Fermi GBM Observation",
  "eventId": "GRB 251001B",
  "format": "text/plain"
}