{
  "createdOn": 1769624799918,
  "submittedHow": "web",
  "submitter": "atrigg2@lsu.edu",
  "circularId": 43546,
  "eventId": "GRB 260127A",
  "body": "A. C. Trigg (NPP ORAU, NASA MSFC) reports on behalf of the Fermi Gamma-ray Burst Monitor Team:\n\n\"At 17:51:07.74 UT on 27 January 2026, the Fermi Gamma-ray Burst Monitor (GBM)\ntriggered and located GRB 260127A (trigger 791229072/260127744),\nwhich was also detected by Swift BAT and XRT (N. J. Klingler et al. 2026, GCN 43529).\nThe Fermi GBM real-time localization (GCN 43528) is consistent with the Swift BAT position.\n\nThe angle from the Fermi LAT boresight is 88 degrees.\n\nThe GBM light curve single emission episode with a duration (T90)\nof about 36 s (50-300 keV). The time-averaged spectrum\nfrom T0-15 to T0+32 s is best fit by\na power law function.\nThe power law index is -1.55 +/- 0.04.\nA Comptonized model fits the spectra equally well with power law index is -1.29 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 490 +/- 25 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(3.8 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured\nstarting from T0-0.32 s in the 10-1000 keV band is 2.7 +/- 0.5 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/\"",
  "format": "text/plain",
  "bibcode": "2026GCN.43546....1T",
  "subject": "GRB 260127A: Fermi GBM Observation"
}