TITLE: GCN CIRCULAR NUMBER: 14803 SUBJECT: Konus-Wind observation of GRB 130606B DATE: 13/06/07 11:35:33 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 hard-spectrum GRB 130606B (Fermi-LAT detection: Vianello et al., GCN 14795; Fermi-GBM detection: Yu, GCN 14801) triggered Konus-Wind at T0=42940.544s UT (11:55:40.544). The light curve shows a bright hard pulse complex from ~T0 to ~T0+70 s, followed by a weak soft tail of emission out to ~T0+100s. The emission at the main phase is seen up to ~17 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB130606_T42940/ Periodic `dips' visible in the 64-ms light curve are due to the source occultation by the spacecraft. As observed by Konus-Wind, the burst had a fluence of (4.3 ± 0.1)x10-4 erg/cm2, and a 64-ms peak flux, measured from T0+8.064s, of (5.7 ± 0.3)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+67.328 s) is best fit in the 100 keV - 18 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -1.25 ± 0.15, the high energy photon index beta = -1.92 ± 0.02, the peak energy Ep = 337 ± 59 keV, chi2 = 120/81 dof. The spectrum at the maximum count rate (measured from T0+7.680 to T0+8.704 s) is best fit in the 50 keV - 18 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.92 ± 0.18, the high energy photon index beta = -1.87 ± 0.10, the peak energy Ep = 690 ± 240 keV, chi2 = 96/90 dof. All the quoted results are preliminary.