TITLE: GCN CIRCULAR NUMBER: 10347 SUBJECT: Konus-Wind observation of GRB 100116A DATE: 10/01/19 13:23:06 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long hard GRB 100116A (Fermi-GBM trigger 285370262: Briggs and Connaughton, GCN 10330; Fermi-LAT localization: McEnery et al., GCN 10333) triggered Konus-Wind at T0=77543.747s UT (21:32:23.747) The burst light curve shows a single-pulse structure with a total duration of ~30 s. A weaker precursor, reported by Fermi-GBM (GCN 10330) is clearly seen in the low-resolution background mode data at T0-88s. The emission is seen up to 10 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB100116_T77543/ As observed by Konus-Wind the burst had a fluence of 5.7(+/-0.6)x10-5 erg/cm2, and a 256-ms peak flux measured from T0+6.144s of 4.2(+/-0.4)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+23.296 s) is well be fitted in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep), with alpha = -0.96(-0.06, +0.07), and Ep = 968(-130, +163) keV (chi2 = 105/98 dof). The spectrum of the most intense part of the burst (measured from T0+0.256 to T0+8.192 s) is well fitted in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which alpha = -0.96(+/-0.6), and Ep = 1015(-121, +146) keV (chi2 = 107/101 dof). All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.