TITLE: GCN CIRCULAR NUMBER: 22355 SUBJECT: Konus-Wind observation of GRB 180113B DATE: 18/01/16 15:18:46 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long GRB 180113B (Fermi-GBM detection: Veres & Meegan, GCN 22329; Insight-HXMT/HE observation: Li et al., GCN 22342; IPN Triangulation: Svinkin et al., GCN 22354) triggered Konus-Wind at T0=958.621 s UT (00:15:58.621). The KW light curve shows a multiple pulses in the interval from ~T0 to ~T0+20 s. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of (4.05 ± 0.29)x10^-5 erg/cm2 and a 64-ms peak energy flux, measured from T0+3.200 s, of (2.2 ± 0.1)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+20.224 s) is best fit in the 20 keV - 15 MeV range by a cutoff power-law (CPL) function with the following model parameters: the photon index alpha = -0.97(-0.07,+0.08), and the peak energy Ep = 559(-58,+71) keV, chi2 = 81/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-2.0. The spectrum near the peak count rate (measured from T0 to T0+3.840 s) is best fit in the 20 keV - 15 MeV range by the CPL function with the following model parameters: the photon index alpha = -0.80(-0.06,+0.06), and the peak energy Ep = 611(-47,+53) keV, chi2 = 93/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-2.0. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180113_T00958/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.