TITLE: GCN CIRCULAR NUMBER: 15338 SUBJECT: Konus-Wind observation of GRB 131014A DATE: 13/10/15 07:56:52 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 very bright GRB 131014A (Fermi GBM detection: Fitzpatrick & Xiong, GCN 15332; Fermi LAT detection: Desiante et al., GCN 15333) triggered Konus-Wind at T0=18541.405 s UT (05:09:01.405). The light curve shows multiple bright, overlapped pulses from ~T0 s to ~T0+6~s. The emission at this phase of the event is seen up to ~12 MeV. The burst was followed by a ~150s-long decaying tail of a weak, soft, extended emission. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB131014_T18541/ As observed by Konus-Wind, the burst had a fluence of (2.05 ± 0.03)x10-4 erg/cm2, and a 64-ms peak flux, measured from T0+1.664 s, of (2.10 ± 0.04)x10-4 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+12.288 s) is best fit in the 50 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.79 ± 0.04, the high energy photon index beta = -2.89 ± 0.08, the peak energy Ep = 346 ± 9 keV, chi2 = 118/94 dof. The spectrum near the maximum count rate (measured from T0+1.536 s to T0+1.792 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.42 ± 0.07, the high energy photon index beta = -2.87 ± 0.13, the peak energy Ep = 607 ± 25 keV, chi2 = 77.5/77 dof. All the quoted results are preliminary.