TITLE: GCN CIRCULAR NUMBER: 17427 SUBJECT: Konus-Wind observation of GRB 150206A DATE: 15/02/09 11:08:41 GMT FROM: Anastasia Tsvetkova at Ioffe Institute S. Golenetskii, R. Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 150206A (Swift BAT trigger 630019: Hagen et al., GCN 17413; Barthelmy et al., GCN 17426; MAXI/GSC detection: Negoro et al., GCN 17414) triggered Konus-Wind at T0=52280.265 s UT (14:31:20.265). The burst light curve shows a broad, multi-peaked pulse with a total duration of ~60 s. The emission is seen up to ~10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150206_T52280/ As observed by Konus-Wind, the burst had a fluence of 5.52(-0.64,+0.69)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+4.320 s, of 7.92(-1.78,+1.83)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+32.256 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.73(-0.14,+0.18), the high energy photon index beta = -2.20(-0.22,+0.15), the peak energy Ep = 228(-35,+37) keV (chi2 = 74/97 dof) The spectrum near the maximum count rate (measured from T0 to T0+7.680 s) is best fit in the 20 keV - 10 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.48(-0.17,+0.21), the high energy photon index beta = -2.20(-0.22,+0.15), the peak energy Ep = 242(-35,+38) keV (chi2 = 84/90 dof) Assuming the redshift z=2.087 (Kruehler et al., GCN 17420) 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 6.0(-0.7,+0.8)x10^53 erg, the peak luminosity L_iso is 2.7(-0.6,+0.6)x10^53 erg/s, and the rest-frame peak energy of the time-integrated spectrum, Ep,i, is 703(-109,+114) keV. All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.