TITLE: GCN CIRCULAR NUMBER: 20977 SUBJECT: Konus-Wind observation of GRB 170403A (short/hard) DATE: 17/04/04 15:25:20 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 short GRB 170403A (Fermi-GBM observation: Roberts & Meegan, GCN 20975; IPN triangulation: Svinkin et al., GCN 20976) triggered Konus-Wind at T0=50358.544 s UT (13:59:18.544). The light curve shows a single pulse with a duration of ~0.12s. As observed by Konus-Wind, the burst had a fluence of (5.4 ± 0.8)x10^-7 erg/cm2 and a 16-ms peak energy flux, measured from T0-0.016, of (7.6 ± 1.8)x10^-6 erg/cm2 (both in the 20 keV - 10 MeV energy range). The time-integrated 3-channel spectrum of the burst, measured from T0-0.064 s to T0+0.064 s, can be modeled by an exponentially cutoff power law with alpha = -0.16 (-0.36, +0.46) and Ep = 357(-58,+90) keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB170403_T50358/ All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.