TITLE: GCN CIRCULAR NUMBER: 17753 SUBJECT: GRB 150424B: Fermi GBM detection DATE: 15/04/24 18:34:27 GMT FROM: Binbin Zhang at UAH Bin-Bin Zhang (UAH) and A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "At 09:39:59.68 UT on 24 April 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150424B (trigger 451561202 / 150424403), which was also detected by the MAXI/GSC (Ono et al. 2015, GCN 17746). The GBM on-ground location is consistent with the MAXI/GSC position. The angle from the Fermi LAT boresight is about 107 degrees. The GBM light curve shows a single pulse with a duration (T90) of about 36.1 s (50-300 keV). The time-averaged spectrum from T0-8 s to T0+28 s is best fit by a Band function with Epeak = 56.6 +/- 8.1 keV, alpha = -0.8 +/- 0.3, and beta = -2.4 +/- 0.2. The event fluence (10-1000 keV) in this time interval is (3.85 +/- 0.31)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0-0.4 s in the 10-1000 keV band is 3.8 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."