TITLE: GCN CIRCULAR NUMBER: 15923 SUBJECT: GRB 140304A: Fermi GBM detection DATE: 14/03/04 22:27:39 GMT FROM: Peter Jenke at MSFC P. Jenke (UAH) and G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team: "At 13:22:31.48 UT on March 4 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140304A (trigger 415632154/140304577), which was also detected by Swift (P. A. Evans et al. 2014, GCN 15915). The GBM on-ground location, using the Fermi GBM trigger data, is consistent with the Swift/XRT location. The angle of the burst direction to the Fermi LAT boresight is 80 degrees. The GBM light curve consists of two main peaks with a combined duration (T90) of 32 +/- 6 s (50-300 keV). The time-averaged spectrum from T0-5 s to T0+14 s is well fit by a power law function with an exponential high energy cutoff. The power law index is -1.1 +/- 0.1 and the high energy cutoff, parameterized as EPeak, is 185 +/- 35 keV. The event fluence (10-1000 keV) in this time interval is (2.6 +/- 0.2)E-06 erg/cm^2. The 1.0-sec peak photon flux measured starting from T0+7.2 s in the 10-1000 keV band is 2.5 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."