TITLE: GCN CIRCULAR NUMBER: 8562 SUBJECT: Konus-Wind observation of GRB 081126 DATE: 08/11/27 14:52:48 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team report: The long GRB 081126 (Margutti et al., GCN 8554, Sato et al. GCN 8557) triggered Konus-Wind at T0=77649.857 s UT (21:34:09.857). The burst light curve shows a precursor at ~T0-20 s and two main pulse at ~T0-3 s and ~T0+28 s with a total duration of ~60 s. As observed by Konus-Wind the burst had a fluence of 9.91(-1.46, +1.57)x10^-6 erg/cm2, and a 256-ms peak flux measured from T0+1.808 s of (1.65 +/- 0.36)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+41.216 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 = -0.82(-0.26, +0.32) , and Ep = 315(-71, +123) keV (chi2 = 68.0/61 dof). Fitting by GRBM (Band) model yields only an upper limit on the high energy photon index: beta < -2.16. All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB081126_T77649/