GCN Circular 21319
R. Hamburg (UAH), C. Meegan (UAH), and E. Bissaldi (Politecnico & INFN Bari): report on behalf of the Fermi GBM Team: "At 08:10:08.00 UT on 10 July 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 170710B (trigger 521367012 / 170710340) which was also detected by the Swift/BAT (D. Palmer et al. 2017, GCN 21316) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 49 degrees. The GBM light curve consists of one main peak with a duration (T90) of about 42 s (50-300 keV). The time-averaged spectrum from T0-4 s to T0+28 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -1.2 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 293 +/- 61 keV. A Band function fits the spectrum equally well with Epeak= 149 +/- 49 keV, alpha = -0.9 +/- 0.2 and beta = -1.9 +/- 0.2. The event fluence (10-1000 keV) in this time interval is (6.0 +/- 0.4)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.5 s in the 10-1000 keV band is 2.7 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."