TITLE: GCN CIRCULAR NUMBER: 28744 SUBJECT: Konus-Wind detection of GRB 201020A DATE: 20/10/22 12:51:04 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 201020A (Swift-BAT trigger #1000926: Ambrosi et al., GCN 28696; Sakamoto et al., GCN 28705; T0(BAT)=05:47:26.16 UT; Fermi-GBM observation: Bissaldi et al., GCN 28706) was detected by Konus-Wind (KW) in the waiting mode. The burst light curve shows a single emission episode with a duration of ~ 15 s. The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB201020A/ As observed by Konus-Wind, the burst had a fluence of 1.38(-0.23,0.45)x10^-6 erg/cm2 and a 2.944-s peak flux, measured from ~T0(BAT)+16.5 s, of 1.34(-0.28,+0.47)x10^-7 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The K-W 3-channel time-integrated spectrum (from ~T0(BAT)+10.6 s to ~T0(BAT)+25.3 s) is best described by simple power-law model with photon index of -2.41(-0.12,+0.17), chi2=0.06/1 dof. Assuming the redshift z=2.903 (Kann et al., GCN 28717) and a standard cosmology model with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014), we estimate the following rest-frame parameters: the isotropic energy release E_iso is ~2.6x10^52 erg, and the peak luminosity L_iso is ~1.0x10^52 erg/s. All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.