TITLE: GCN CIRCULAR NUMBER: 16759 SUBJECT: GRB 140829A: Fermi GBM Detection DATE: 14/08/31 20:50:38 GMT FROM: Matthew Stanbro at UAH/Fermi M. Stanbro (UAH) reports on behalf of the Fermi GBM Team: "At 21:07:27.47 UT on 29 August 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140829A (trigger 431039250 / 140829880). The GBM error circle was also observed with iPTF in search of an optical counterpart of the GRB; no credible counterpart was found (Singer et. al., 2014, GCN 16758). The GBM light curve consists of a double pulse with a duration (T90) of about 19 s (50-300 keV). The time-averaged spectrum from T0-3.1 s to T0+18.4 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.5 +/- 0.2 and the cutoff energy, parameterized as Epeak, is 324 +/- 43 keV. The event fluence (10-1000 keV) in this time interval is (5.12 +/- 0.41)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+11.52 s in the 10-1000 keV band is 2.9 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."