TITLE: GCN CIRCULAR NUMBER: 17811 SUBJECT: GRB 150512A: Fermi GBM detection DATE: 15/05/13 21:53:22 GMT FROM: Binbin Zhang at UAH Bin-Bin Zhang (UAH) and A. von Kienlin (MPE) report on behalf of the Fermi GBM Team: "At 10:22:25.87 UT on 12 May 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150512A (trigger 453118948 / 150512432), which was also detected by the iPTF (Singer et al. 2015,GCN 17809). The GBM on-ground location is consistent with the positions of the potential transient sources reported by iPTF (Singer et al. 2015, GCN 17809). The angle of the burst direction to the Fermi LAT boresight was 95 degrees. The GBM light curve consists of several peaks with a total duration (T90) of about 123 s (50-300 keV). The time-averaged spectrum from T0-20 s to T0+104 s is best fit by a BAND function with Epeak = 121.5 +/- 18.7 keV, alpha = -0.9 +/- 0.1 and Beta = -2.0 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (2.17 +/- 0.06)E-05 erg/cm^2. The 1.0-sec peak photon flux measured starting from T0+101 s in the 10-1000 keV band is 5.5 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."