GCN Circular 31565
S. Lesage (UAH) reports on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 23:00:50 UT on 09 February 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220209A (trigger 666140455/220209959) which was also detected by AGILE (A. Ursi, et al. 2022, GCN 31563) and GECAM (Y. Q. Zhang, et al. 2022, GCN 31564). The Fermi GBM Final Real-time Localization (GCN 31561) is consistent with the GECAM position. The GBM light curve shows two bright emission episodes with a duration (T90) of about 201 s (10-1000 keV). The time-averaged spectrum for the first emission episode from T0+7.2 to T0+51.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.92 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 1097 +/- 118 keV. The event fluence (10-1000 keV) in this time interval is (3.48 +/- 0.05)E-05 erg/cm^2. The time-averaged spectrum for the second emission episode from T0+159.7 to T0+220.2 s is also best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.95 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 307 +/- 12 keV. The event fluence (10-1000 keV) in this time interval is (2.6 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+198.3 s in the 10-1000 keV band is 17.8 +/- 0.4 ph/s/cm^2. 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/"