TITLE: GCN CIRCULAR NUMBER: 31604 SUBJECT: Konus-Wind detection of GRB 220209A DATE: 22/02/18 17:54:23 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, D. Frederiks, M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 220209A (Fermi-GBM detection: The Fermi GBM team, GCN Circ. 31561; Lesage eat al., GCN Circ. 31565; AGILE-MCAL detection: Ursi et al., GCN Circ. 31563; GECAM detection: Zhang et al., GCN Circ. 31564; Fermi-LAT detection: Pesce-Rollins et al., GCN Circ. 31577; IPN triangulation: Kozyrev et al., GCN Circ. 31598) triggered Konus-Wind at T0=82859.23 s UT (23:00:59.230). The burst light curve shows two emission episodes. The first one, lasting from ~T0-12 s to ~T0+98 s, and the second episode, from ~T0+147 s to ~T0+260 s. The total burst duration was ~272 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/GRB220209_T82859/ As observed by Konus-Wind, the burst had a fluence of 1.86(-0.32,+0.42)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+1.312 s, of 1.12(-0.28,+0.29)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+218.624 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 = -0.83(-0.19,+0.60), the high energy photon index beta = -1.81(-0.21,+0.16), the peak energy Ep = 320(-162,+162) keV (chi2 = 101/86 dof). The spectrum near the maximum count rate (measured from T0 to T0+7.936 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 = -0.89(-0.05,+0.06), the high energy photon index beta = -3.17(-6.83,+0.89), the peak energy Ep = 1675(-288,+289) keV (chi2 = 96/86 dof). All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.