{
  "body": "P. Veres (UAH) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 03:26:31.86 UT on 28 October 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251028A (trigger 783314796/251028143) which was also detected by MAXI (Negoro et al. 2025, GCN 42498) and Glowbug (Cheung et al. 2025, GCN 42506). The Fermi GBM on-ground location is consistent with the MAXI position.\n\nThe angle from the Fermi LAT boresight is 50 degrees.\n\nThe GBM light curve consists of multiple overlapping pulses with a duration (T90)\nof about 30 s (50-300 keV). The time-averaged spectrum\nfrom T0 to T0+39.9 s is best fit by\na Band function with Epeak = 244 +/- 14 keV,\nalpha = -0.91 +/- 0.03, and beta = -2.4 +/- 0.1.\n\nThe event fluence (10-1000 keV) in this time interval is\n(3.13 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+24 s in the 10-1000 keV band is 10.8 +/- 0.3 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/\"\n",
  "bibcode": "2025GCN.42520....1V",
  "circularId": 42520,
  "format": "text/plain",
  "submittedHow": "web",
  "createdOn": 1761768492939,
  "submitter": "Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>",
  "eventId": "GRB 251028A",
  "subject": "GRB 251028A: Fermi GBM Observation"
}