{
  "eventId": "GRB 251003A",
  "body": "Jacob Smith (UAH) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 01:58:31.96 UT on 03 October 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 251003A (trigger 781149516/251003082),\nwhich was also detected by Swift BAT (A. P. Beardmore et al. 2025, GCN 42070).\nThe Fermi GBM on-ground location is consistent with the Swift BAT position.\nGTC/OSIRIS+ detected a spectroscopic redshift z = 4.412 (R. Sanchez-Ramirez et al. 2025, GCN 42086).\n\nThe angle from the Fermi LAT boresight is 56 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 10 s (50-300 keV). The time-averaged spectrum\nfrom T0-4.1 to T0+6.1 s is best fit by\na simple power law function with index -1.7 +/- 0.1.\nA Comptonized function fits equally well with a Epeak of 118 +/- 35 and alpha of -1.3 +/- 0.2.\n\nThe event fluence (10-1000 keV) in this time interval is\n(1.1 +/- 0.1)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 1.6 +/- 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/\"",
  "submittedHow": "web",
  "bibcode": "2025GCN.42170....1S",
  "createdOn": 1759947009039,
  "format": "text/plain",
  "circularId": 42170,
  "submitter": "Jacob Smith at Fermi-GBM Team <jrs0118@uah.edu>",
  "subject": "GRB 251003A: Fermi GBM Observation"
}