{
  "circularId": 43144,
  "createdOn": 1765909895221,
  "submittedHow": "web",
  "eventId": "GRB 251215A",
  "body": "P. Veres (UAH) and C. Meegan (UAH) report on behalf of\nthe Fermi Gamma-ray Burst Monitor Team:\n\n\"At 04:21:21.57 UT on 15 December 2025, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 251215A (trigger 787465286/251215181),\nwhich was also detected by Swift-BAT-GUANO (Ronchini et al. 2025, GCN 43114), Swift-XRT (Osborne et al. 2025, GCN 43137) and Glowbug (Cheung et al. 2025, GCN 43133).\nThe real-time  Fermi GBM location (GCN 43104) is consistent with the Swift-BAT position.\n\nThe GBM light curve consists of multiple overlapping pulses with a duration (T90)\nof about 143 s (50-300 keV). The time-averaged spectrum\nfrom T0-37 to T0+162 s is best fit by\na Band function with Epeak = 35 +/- 7 keV,\nalpha = -1 +/- 0.3, and beta = -1.97 +/- 0.03.\n\nThe event fluence (10-1000 keV) in this time interval is\n(2.05 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0+64 s in the 10-1000 keV band is 5.7 +/- 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/\"\n",
  "format": "text/plain",
  "submitter": "Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>",
  "subject": "GRB 251215A: Fermi GBM Observation",
  "bibcode": "2025GCN.43144....1V"
}