TITLE: GCN CIRCULAR NUMBER: 14856 SUBJECT: Konus-Wind observation of GRB 130609B DATE: 13/06/10 16:22:33 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 130609B (Swift-BAT trigger 557828: Krimm, et al., GCN 14841) triggered Konus-Wind at T0=77916.818 s UT (21:38:36.818) The light curve consists of two major emission episodes: the first one with a bright multi-peaked structure from ~T0-30 s to ~T0+55 s, and the second, much weaker and softer episode, from ~T0+170 s to ~T0+210 s. The emission is seen up to 7 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130609_T77916/ As observed by Konus-Wind, the burst had a fluence of (9.4 ± 0.7)x10-5 erg/cm2, and a 64-ms peak flux, measured from T0+3.712 s, of (9.5 ± 0.6)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the first emission episode (measured from T0 to T0+54.528 s) is best fit in the 20 keV - 18 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.84 ± 0.05, the high energy photon index beta = -2.39 ± 0.15, the peak energy Ep = 397 ± 26 keV, chi2 = 97/97 dof. The time-averaged spectrum of the second emission episode (measured from T0+169.216 to T0+210.176 s) is best fit in the 20 keV - 18 MeV range by the cutoff power law with the following model parameters: the photon index alpha = -1.64 ± 0.21, the peak energy Ep = 198 ± 105 keV, chi2 = 93.7/98 dof. The spectrum at the maximum count rate (measured from T0 to T0+6.656 s) is best fit in the 20 keV - 18 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.70 ± 0.07, the high energy photon index beta = -3.0 ± 0.3, the peak energy Ep = 740 ± 90 keV, chi2 = 105/97 dof. All the quoted results are preliminary.