{
  "circularId": 45616,
  "submitter": "atrigg2@lsu.edu",
  "body": "A. C. Trigg (NPP ORAU, NASA MSFC) reports report on behalf of the Fermi Gamma-ray Burst Monitor Team:\n\n\"At 15:11:04.34 UT on 16 September 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located\nGRB 260916B (trigger 811264269/260916633).\n\nThe on-ground calculated location, using the Fermi GBM trigger data, is RA = 352.6, Dec = -35.7 \n(J2000 degrees, equivalent to J2000 23h 27m, -35d 55'), with a statistical uncertainty of 4.6 degrees.\n(radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have\ncharacterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail\nsuffering a larger than 10 deg systematic error [Connaughton et al. 2015, ApJS, 216, 32]).\n\nThe angle from the Fermi LAT boresight is 110 degrees.\n\nThe GBM light curve consistent with a short single emission episode with a duration (T90) of about 0.1\ns (50-300 keV). The time-averaged spectrum from T0-0.07 to T0+0.23 s is best fit by a power law\nfunction with an exponential high-energy cutoff. The power law index is 0.24 +/- 0.01 and the cutoff\nenergy, parameterized as Epeak, is 980 +/- 30 keV.\n\nThe event fluence (10-1000 keV) in this time interval is (1.06 +/- 0.07)E-06 erg/cm^2. The 64-ms peak\nphoton flux measured starting from T0+0.00 s in the 10-1000 keV band is 13.4 +/- 1.0 ph/s/cm^2.\n\nThe spectral analysis results presented above are preliminary; final results will be published in the\nGBM GRB Catalog: https://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/\"",
  "eventType": [
    "GRB",
    "Gamma-ray Transient"
  ],
  "createdOn": 1789671149258,
  "subject": "GRB 260916B: Fermi GBM Detection",
  "eventId": "GRB 260916B",
  "submittedHow": "web",
  "format": "text/plain"
}