TITLE: GCN CIRCULAR NUMBER: 17408 SUBJECT: GRB 150204A: Fermi GBM detection DATE: 15/02/04 21:17:10 GMT FROM: Eric Burns at U of Alabama E. Burns (UAH) and H.-F. Yu (MPE) report on behalf of the Fermi GBM Team: "At 06:31:07.88 UT on 04 February 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150204A (trigger 444724270 / 150204272) which was also found in ground analysis of Swift/BAT data (Cummings et al. 2015, GCN 17404). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 54 degrees. The GBM light curve consists of one main peak with a duration (T90) of about 10 s (50-300 keV). The time-averaged spectrum from T0-6.144 s to T0+7.168 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.4 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 350 +/- 143 keV The event fluence (10-1000 keV) in this time interval is (2.2 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.064 s in the 10-1000 keV band is 3.1 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."