TITLE: GCN CIRCULAR NUMBER: 22914 SUBJECT: Konus-Wind observation of GRB 180703B DATE: 18/07/06 11:56:57 GMT FROM: Dmitry Frederiks at Ioffe Institute D. Frederiks, S. Golenetskii, R.Aptekar, A. Kozlova, A.Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report: GRB 180703B (IPN Triangulation: Hurley et al., GCN 22908; Fermi-LAT detection: Racusin et al., GCN 22884; Fermi-GBM detection: Poolakkil & Meegan, GCN 22897) triggered Konus-Wind at T0=82008.633 s UT (22:46:48.633) The burst light curve shows two prominent peaks, with a total duration of ~2.0 s. The emission in the main peak is seen up to ~2 MeV. As observed by Konus-Wind, the burst had a fluence of (6.4 ± 0.4)x10^-6 erg/cm2 and a 64-ms peak energy flux, measured from T0+1.088, of (1.60 ± 0.09)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 2 MeV range by a cutoff power-law (CPL) function with the following model parameters: the photon index alpha = -0.74(-0.18,+0.19), and the peak energy Ep = 131(-9,+11) keV, chi2 = 55/57 dof. Fitting this spectrum with the GRB (Band) function yields the same alpha and Ep, and only an upper limit on beta (<-3.3). The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB180703_T82008/ All the quoted errors are estimated at the 90% confidence level. All the presented results are preliminary.