TITLE: GCN CIRCULAR NUMBER: 20323 SUBJECT: Konus-Wind observation of GRB 161219B DATE: 16/12/21 17:31:16 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 161219A (Swift-BAT trigger #727541: D'Ai et al., GCN 20296; Palmer et al., GCN 20308; T0(BAT)=18:48:19.308 UT) was detected by Konus-Wind (KW) in the waiting mode. The light curve shows a single pulse with a duration of ~10 s. Modeling the KW 3-channel time-integrated spectrum (from T0(BAT)-0.134 s to T0(BAT)+8.698 s) by a power law with exponential cutoff (CPL) model dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -1.59 ± 0.71 and Ep = 91 ± 21 keV. The corresponding 20-1000 keV energy fluence for this time interval is (3.1 ± 0.8)x10^-6 erg/cm2. Assuming the redshift z=0.1475 (Tanvir et al., GCN 20321) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, and Omega_Lambda = 0.73, we estimate the burst isotropic energy release E_iso to ~1.6x10^50 erg and the rest-frame peak energy of the time-integrated spectrum, Ep,i, to ~104 keV. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB161219B/ All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.