TITLE: GCN CIRCULAR NUMBER: 8258 SUBJECT: Konus-Wind observation of GRB 080916C DATE: 08/09/17 11:30:55 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 080916ó (Fermi GBM trigger 243216766/080916.009; Goldstein and van der Horst, GCN 8245; Tajima et al., GCN 8246; Hurley et al., GCN 8251) triggered Konus-Wind at T0=764.632 s UT (00:12:44.632). The burst light curve shows the main part with a duration of ~70 s followed by a weak tail seen at least till ~T0+200 s. As observed by Konus-Wind the burst had a fluence of (1.24 +/- 0.17)x10^-4 erg/cm2, and a 256-ms peak flux measured from T0+3.168 s of (1.19 +/- 0.30)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+71.424 s) is well be fitted (in the 20 keV - 10 MeV range) by GRBM (Band) model for which: the low-energy photon index is alpha = -1.040(-0.058, +0.065), the high energy photon index beta = -2.26(-0.40, +0.21), the peak energy Ep = 505(-70, +79) keV (chi2 = 75.6/84 dof). All the quoted errors are at the 90% confidence level. The Konus-Wind light curve of this GRB is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080916_T00764/