TITLE: GCN CIRCULAR NUMBER: 20238 SUBJECT: Konus-Wind observation of GRB 161202A DATE: 16/12/06 16:44:29 GMT FROM: Anna Kozlova at Ioffe Institute A.Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, 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 161202A (Swift-BAT detection and observation: Sbarufatti et al., GCN Circ. 20227, Cummings et al., GCN Circ. 20233; Fermi-LAT detection: Vianello & Longo, GCN Circ. 20229) triggered Konus-Wind at T0=83508.822 s UT (23:11:48.822). The burst light curve shows a multipeaked structure started at ~T0-57.1 s with a total duration of ~181.0 s. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB161202_T83508/ As observed by Konus-Wind, the burst had a fluence of 2.90(-0.40,+0.73)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+3.920 s, of 3.03(-0.80,+0.80)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+139.520 s) is best fit in the 20 keV - 2 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.43(-0.25,+0.30) and Ep = 222(-63,+201) keV (chi2 = 65/62 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high-energy photon index: beta < -1.9 (chi2 = 65/61 dof) The spectrum near the maximum count rate (measured from T0+0.256 to T0+8.448 s) is best fit in the 20 keV - 2 MeV range by the power law with exponential cutoff model: with alpha = -0.67(-0.21,+0.24) and Ep = 203(-20,+26) keV (chi2 = 76/62 dof). Fitting by the GRB (Band) model yields the same alpha and Ep, and an upper limit on the high-energy photon index: beta < -2.5 (chi2 = 76/61 dof) All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.