TITLE: GCN CIRCULAR NUMBER: 16660 SUBJECT: Konus-Wind observation of GRB 140801A DATE: 14/08/02 12:26:02 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lyssenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 140801A (IPN triangulation: Hurley et al., GCN 16655; Fermi-GBM detection: Pelassa, GCN 16658) triggered Konus-Wind at T0=68394.769 s UT (18:59:54.769). The light curve shows a multi-peaked structure with a total duration of ~7.5 s. The emission is seen up to ~3 MeV. As observed by Konus-Wind, the burst had a fluence of 1.10(-0.04,+0.04)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+0.128 s, of 4.6(-0.6,+0.6)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+7.680 s) is best fit in the 20 keV - 5 MeV range by the cutoff power law with the following model parameters: the photon index alpha = -0.44(-0.17,+0.18), and the peak energy Ep = 108(-4,+5) keV, chi2 = 75/71 dof. Fitting this spectrum with the Band model yields the same values of alpha and Ep with an upper limit on beta of -4.2 The spectrum near the peak count rate (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 5 MeV range by the cutoff power law with the following model parameters: the photon index alpha = +0.38(-0.56,+0.69), and the peak energy Ep = 121(-12,+13) keV, chi2 = 27/24 dof. Assuming the redshift z=1.320 (de Ugarte Postigo et al., GCN 16657) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, and Omega_Lambda = 0.73, we estimate the following rest-frame parameters: the isotropic energy release E_iso is ~4.9x10^52 erg, the peak luminosity L_iso is ~5.0x10^52 erg/s, and the rest-frame peak energy of the time-integrated spectrum, Ep,i, is ~250 keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB140801_T68394/ All the quoted errors are at the 90% sigma confidence level. All the quoted values are preliminary.