{
  "submittedHow": "web",
  "format": "text/plain",
  "circularId": 45830,
  "submitter": "Christian Malacaria at INAF-OAR <cmalacaria.astro@gmail.com>",
  "eventId": "GRB 261007A",
  "body": "C. Malacaria (INAF-OAR) report report on behalf of the Fermi Gamma-ray Burst Monitor Team:\n\n\"At 05:39:49.71 UT on 07 October 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 261007A (trigger 813044394/261007236), which was also detected by SVOM/Eclairs (Hatsune Goto et al. 2026, GCN 45824), EP (W.F. Wen et al. 2026, GCN 45828), KAIT (W. Zheng et al. 2026, GCN 45825), and VLT (A. Saccardi et al. 2026, GCN 45829825) with a spectroscopic redshift of z = 2.101.\nThe Fermi GBM on-ground location is consistent with the SVOM/Eclairs position.\n\nThe angle from the Fermi LAT boresight is 92 degrees.\n\nThe GBM light curve consists of multiple bright peaks with a duration (T90) of about 22.8 s (50-300 keV).\nThe time-averaged spectrum from T0 to T0+36 s is best fit by a power law function with an exponential high-energy cutoff.\nThe power law index is -0.61 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 300 +/- 4 keV.\n\nThe event fluence (10-1000 keV) in this time interval is (9.01 +/- 0.07)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+21.7 s in the 10-1000 keV band is 43.5 +/- 0.5 ph/s/cm^2.\n\nA Band function fits the spectrum equally well with Epeak = 293 +/- 5 keV, alpha = -0.60 +/- 0.01 and beta = -3.3 +/- 0.3.\n\nThe spectral analysis results presented above are preliminary; final results will be published in the GBM 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: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/\"",
  "eventType": [
    "GRB",
    "Gamma-ray Transient"
  ],
  "createdOn": 1791366908646,
  "subject": "GRB 261007A: Fermi GBM observation"
}