TITLE: GCN CIRCULAR NUMBER: 32994 SUBJECT: GRB 221126A: Fermi GBM observation DATE: 22/11/29 11:59:03 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 13:07:29.94 UT on 26 November 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 221126A (trigger 691160854 / 221126547). This event was also observed by Swift/BAT-GUANO (GCN 32987), AstroSat CZTI (GCN 32990) and AGILE (GCN 32992). The GBM position is reported in the Fermi-GBM Final on-ground Localization (GCN 32985). The angle from the Fermi LAT boresight is 22 degrees. The GBM light curve shows a structured pulse with a duration (T90) of about 7 s (50-300 keV). The time-averaged spectrum from T0-0.90 s to T0+8.32 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.94 +/- 0.03 and the cutoff energy, parameterized as Epeak, is 194 +/- 8 keV The event fluence (10-1000 keV) in this time interval is (9.29 +/- 0.02)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+4.224 s in the 10-1000 keV band is 15.7 +/- 0.4 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 190 +/- 10 keV, alpha = -0.92 +/- 0.04 and beta = -3.1 +/- 0.6. The 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 For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"