TITLE: GCN CIRCULAR NUMBER: 12456 SUBJECT: Konus-Wind observation of GRB 111016B DATE: 11/10/19 08:50:35 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 intense GRB 111016B (localized by IPN: Hurley et al., GCN 12452) triggered Konus-Wind at T0=81700.723s UT (22:41:40.723) The light curve shows a multi-peaked complex with a total duration of ~150 s. The emission is seen up to ~5 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB111016_T81700/ As observed by Konus-Wind the burst had a fluence of 1.37(-0.05,+0.05)x10-4 erg/cm2, and a 256-ms peak flux, measured from T0+1.792 s, of 3.7(-0.3,+0.3)x10-6 erg/cm2/s (both in the 20 keV - 5 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+145.408 s) is best fitted in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which alpha = -0.78 (-0.06, +0.06), and Ep = 378(-19, +21) keV, chi2 = 58.7/76 dof. Fitting this spectrum by the GRB (Band) function yields the same alpha and Ep with a high energy photon index beta < -3.0 (chi2 = 58.7/75 dof). The spectrum at the maximum count rate (measured from T0 to T0+6.144 s) is best fitted in the 20 keV - 5 MeV range by a power law with exponential cutoff model, for which alpha = -0.72 (-0.10, +0.11), and Ep = 327(-26, +30) keV, chi2 = 86.4/76 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.