TITLE: GCN CIRCULAR NUMBER: 22344 SUBJECT: Konus-Wind observation of GRB 180113A DATE: 18/01/15 15:37:30 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 180113A (Swift/BAT detection: Ukwatta et al., GCN 22325, GCN 22332; Fermi-GBM detection: Veres, GCN 22328) triggered Konus-Wind at T0=10027.005 s UT (02:47:07.005). The KW light curve shows a single pulse with a total duration of ~13 s. The emission is seen up to ~1 MeV. As observed by Konus-Wind, the burst had a fluence of (1.36 ± 0.10)x10^-5 erg/cm2 and a 64-ms peak energy flux, measured from T0+0.448, of (3.1 ± 0.3)x10^-6 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+16.640 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 = -0.80(-0.12,+0.13), and the peak energy Ep = 293(-29,+36) keV, chi2 = 72/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-3.0. The spectrum near the peak count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 15 MeV range by the CPL function with the following model parameters: the photon index alpha = -0.72(-0.12,+0.13), and the peak energy Ep = 308(-30,+36) keV, chi2 = 83/98 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and an upper limit on beta of ~-3.0. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180113_T10027/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.