GCN Circular 33083
O.J. Roberts (USRA/NASA), J. Wood (NASA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 04:14:27.97 UT on 15 December 2022, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 221215A (trigger 692770472 / 221215177) which was also detected by the Swift/BAT GUANO (DeLaunay et al. 2022, GCN 33062) The Fermi GBM Final Real-time Localization (GCN 33054) is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 53 degrees. The GBM light curve shows a FRED-like pulse with a duration (T90) of about 14 s (50-300 keV). The time-averaged spectrum from T0-2 s to T0+12 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is 1.6 +/- 1.3 and the cutoff energy, parameterized as Epeak, is 165 +/- 26 keV The event fluence (10-1000 keV) in this time interval is (6.8 +/- 1.2)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.7 s in the 10-1000 keV band is 29.8 +/- 9.4 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/"