TITLE: GCN CIRCULAR NUMBER: 8721 SUBJECT: Konus-Wind observation of GRB 081222 DATE: 08/12/24 14:14:00 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 081222 (Swift-BAT trigger #337914: Grupe et al., GCN 8691; Fenimore et al., GCN 8709) triggered Konus-Wind at T0=17642.534 s UT (04:54:02.534). The burst light curve shows a single pulse with a duration of ~12 s. There is a hint of the weak tail detected by the Swift-BAT (Fenimore et al., GCN 8709) in the K-W G1 band (~20-80 keV). As observed by Konus-Wind the burst had a fluence of 1.32(-0.40, +0.48)x10^-5 erg/cm2, and a 256-ms peak flux measured from T0+4.688 s of 2.22(-0.73, +0.87)x10^-6 erg/cm2/s (both in the 20 keV - 1 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+16.640 s) can be fitted (in the 20 keV - 1 MeV range) by GRB (Band) model for which: the low-energy photon index is alpha = -0.67(-0.33, +0.39), the high energy photon index beta = -2.35(-1.25, +0.30), the peak energy Ep = 165(-29, +47) keV (chi2 = 63.0/51 dof). All the quoted errors are at the 90% confidence level. Assuming z = 2.77 (Cucchiara et al., GCN 8713; Graham et al., GCN 8718) and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27, Omega_\Lambda = 0.73, the isotropic energy release E_iso ~2.4x10^53 erg, the peak luminosity (L_iso)_max ~ 1.5x10^53 erg/s, and Ep_rest ~600 keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB081222_T17642/