TITLE: GCN CIRCULAR NUMBER: 19056 SUBJECT: GRB 160221A: Fermi GBM observation DATE: 16/02/22 17:38:49 GMT FROM: C. Michelle Hui at MSFC/Fermi-GBM C. M. Hui (NASA/MSFC) and E. Bissaldi (Politecnico & INFN Bari) report on behalf of the Fermi GBM Team: "At 23:49:45.22 UT on 21 February 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160221A (trigger 477791389 / 160221993), which was also detected by INTEGRAL (Mereghetti et al., GCN 19046). The GBM on-ground location is consistent with the INTEGRAL position. The angle from the Fermi LAT boresight at the GBM trigger time is 58 degrees. The GBM light curve consists of a single pulse with a duration (T90) of about 15 s (50-300 keV). The time-averaged spectrum from T0-1.5 s to T0+5.6 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.15 +/- 0.16 and the cutoff energy, parameterized as Epeak, is 67 +/- 7 keV. The event fluence (10-1000 keV) in this time interval is (1.55 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+2.2 s in the 10-1000 keV band is 4.0 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."