TITLE: GCN CIRCULAR NUMBER: 6960 SUBJECT: Konus-Wind observation of GRB 071020 DATE: 07/10/21 13:31:43 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T. Cline on behalf of the Konus-Wind team report: The long GRB 071020 (Swift-BAT trigger #294835: Holland et al., GCN 6949, Tueller et al., GCN 6954) triggered Konus-Wind at T0=25346.637 s UT (07:02:26.637). The burst light curve shows a multipeaked structure with a duration of ~3.5 s. As observed by Konus-Wind the burst had a fluence of 7.71(-4.76, +0.39)x10^-6 erg/cm2, and a 64-ms peak flux measured from T0+2.416 s of 6.04(-3.88, +1.12)x10^-6 erg/cm2/s (both in the 20 keV - 2 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+8.448 s) is well fitted (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 = 0.65(-0.32, +0.27) and Ep = 322(-53, +80) keV (chi2 = 64.4/61 dof). Fitting by GRBM (Band) model yields only an upper limit on the high energy photon index: beta < -1.97. All the quoted errors are at the 90% confidence level. Assuming z = 2.145 (Jakobsson et al., GCN 6952) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.3, Omega_\Lambda = 0.7, the isotropic bolometric energy release is E_iso ~8x10^52 erg, and the maximum bolometric luminosity is (L_iso)_max ~2x10^53 erg/s. The Konus-Wind light curve of this GRB is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB071020_T25346/