TITLE: GCN CIRCULAR NUMBER: 15428 SUBJECT: Konus-Wind observation of GRB 131031A DATE: 13/11/01 09:21:25 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 131031A (Cummings, GCN 15421) triggered Konus-Wind at T0=41619.496 s UT (11:33:39.496). The burst light curve shows a multi-peaked structure from ~T0-0.5 s till ~T0+6 s. The emission is seen up to ~7 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB131031_T41619/ As observed by Konus-Wind, the burst had a fluence of (4.8 ± 1.2)x10-6 erg/cm2, and a 64-ms peak flux, measured from T0+0.064 s, of (3.8 ± 0.5)x10-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by a simple power law with the photon index 2.09 ± 0.15, chi2 = 82.5/99 dof. The spectrum at the maximum count rate (measured from T0 to T0+0.256 s) is best fit in the 20 keV - 15 MeV range by a simple power law with the photon index 1.96 ± 0.18, chi2 = 51.3/72 dof. All the quoted values are preliminary.