TITLE: GCN CIRCULAR NUMBER: 15203 SUBJECT: Konus-Wind observation of GRB 130907A DATE: 13/09/09 10:52:42 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long-duration intense GRB 130907A (Swift-BAT trigger 569992: Page, et al., GCN 15183; Cummings, et al., GCN 15202) triggered Konus-Wind at T0=77955.997 s UT (21:39:15.997), or ~118 s before the BAT trigger. The burst light curve shows multiple bright, partially overlapped pulses from ~T0-4 s till ~T0+210~s. The emission is seen up to ~15 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130907_T77955/ As observed by Konus-Wind, the burst had a fluence of (7.9 ± 0.5)x10-4 erg/cm2, and a 256-ms peak flux, measured from T0+139.008 s, of (2.2 ± 0.1)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+206.080 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.91 ± 0.02, the high energy photon index beta = -2.42 ± 0.07, the peak energy Ep = 394 ± 11 keV, chi2 = 90/92 dof. The spectrum near the maximum count rate (measured from T0+139.264 s to T0+143.872 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.65 ± 0.03, the high energy photon index beta = -2.22 ± 0.05, the peak energy Ep = 390 ± 16 keV, chi2 = 111/96 dof. Assuming the NOT redshift z=1.238 (de Ugarte Postigo, et al., GCN 15187), 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 of GRB 130907A: the isotropic energy release E_iso is (3.3 ± 0.1)x10^54 erg, the peak luminosity L_iso is (2.0 ± 0.1)x10^53 erg/s, and the rest-frame peak energy Ep,i = (880 ± 25) keV All the quoted results are preliminary.