TITLE: GCN CIRCULAR NUMBER: 20614 SUBJECT: Konus-Wind observation of GRB 170205A DATE: 17/02/06 16:19:11 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Kozlova, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 170205A (Swift-BAT detection: Troja et al., GCN Circ. 20603), triggered Konus-Wind at T0=45549.824 s UT (12:39:09.824). The burst light curve shows a double-peaked structure which started at ~T0-32 s and had a total duration of ~56 s. The emission is seen up to ~1 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170205_T45549/ As observed by Konus-Wind, the burst had a fluence of 1.22(-0.20,+0.24)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0-0.220 s, of 3.29(-1.62,+1.99)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+24.832 s) is best fit in the 20 keV - 10 MeV range by a power law with spectral index = -2.19(-0.12,+0.13) (chi2 = 58/69 dof). Fitting this spectrum by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -1.75 (-0.24,+0.62) and an upper limit on Ep of 75 keV (chi2 = 56/68 dof). For the CPL model, the burst fluence is 6.2(-0.8,+1.4)x10^-6 erg/cm2, and the 64-ms peak flux is 1.8(-0.8,+2.8)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.