TITLE: GCN CIRCULAR NUMBER: 17220 SUBJECT: GRB 141222A: Fermi GBM detection DATE: 14/12/22 18:56:06 GMT FROM: Peter Jenke at MSFC P. Jenke (UAH) reports on behalf of the Fermi GBM Team: "At 07:08:57.40 UT on December 22 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 141222A (trigger 440924940/141222298), which was also detected by Fermi/LAT (J. McEnery et al. 2014, GCN 17218). The GBM on-ground location, using the Fermi GBM trigger data, is consistent with the Fermi/LAT location. The angle of the burst direction to the Fermi LAT boresight is 46 degrees. The GBM light curve consists of a narrow peak followed by a broad peak with a tail. The duration (T90) is about 2.4 s (50-300 keV). The time-averaged spectrum from T0-0.06 s to T0+1.41 s is adequately fit by a Band function with Epeak = 2427 +/- 580 keV, Alpha =-1.49 +/- 0.01 and Beta = -1.74 +/- 0.05. The event fluence (10-1000 keV) in this time interval is (8.16 +/- 0.08)E-06 erg/cm^2. The 64 ms peak photon flux measured starting from T0+0.64 s in the 10-1000 keV band is 121 +/- 3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."