{
  "bibcode": "2025GCN.39033....1V",
  "eventId": "GRB 250118A",
  "body": "P. Veres (UAH) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 18:31:11.97 UT on 18 January 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 250118A (trigger 758917876/250118772).\nwhich was also detected by Swift-BAT/GUANO (Ronchini et al. 2025, GCN 39004).\nThe Fermi GBM on-ground location is consistent with the Swift position.\n\nThe angle from the Fermi LAT boresight is 14 degrees.\n\nThe GBM light curve consists of a single emission episode with a duration (T90)\nof about 0.3 s (50-300 keV). The time-averaged spectrum\nfrom T0-0.13 to T0+0.06 s is best fit by\na simple power law function with index -1.18 +/- 0.06.\n\nThe event fluence (10-1000 keV) in this time interval is\n(4.1 +/- 0.4)E-07 erg/cm^2. The 64-ms peak photon flux measured\nstarting from T0-0.064 s in the 10-1000 keV band is 7.4 +/- 0.9 ph/s/cm^2.\n\nA power law function with an exponential high-energy cutoff gives an acceptable fit to the spectrum.\nThe power law index is -0.73 +/- 0.22 and the cutoff energy,\nparameterized as Epeak, is 1100 +/- 500 keV.\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/\"",
  "subject": "GRB 250118A: Fermi GBM Observation",
  "submitter": "Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>",
  "submittedHow": "web",
  "circularId": 39033,
  "createdOn": 1737836953501,
  "format": "text/plain"
}