TITLE: GCN CIRCULAR NUMBER: 17793 SUBJECT: GRB 150430A: Fermi GBM Detection DATE: 15/04/30 14:28:30 GMT FROM: Oliver Roberts at UCD/Fermi O.J. Roberts (UCD) and G. Younes (USRA at GWU) report on behalf of the Fermi GBM Team: "At 00:21:05.65 UT on the 30th of April 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150430A (trigger 452046068 / 150430015), which was also detected by Swift (D'Elia et al. 2015, GCN 17789) and MAXI/GSC (Negoro et al. 2015, GCN 17791). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is about 110 degrees. The GBM light curve shows several bright pulses over a duration (T90) of 116.7 s (50-300 keV). The time-averaged spectrum from T0-4.1 s to T0+111.6 s is well fit by power law function with an exponential high-energy cutoff. The power law index is -0.95 +/- 0.15 and the cutoff energy, parameterized as Epeak, is 346 +/- 57 keV. The event fluence (10-1000 keV) in this time interval is (2.1 +/- 0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+10.3 s in the 10-1000 keV band is 9.7 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."