TITLE: GCN CIRCULAR NUMBER: 27399 SUBJECT: Konus-Wind observation of GRB 200313A DATE: 20/03/17 13:49:15 GMT FROM: Anna Ridnaia at Ioffe Institute A. Ridnaia, S. Golenetskii, R. Aptekar, D. Frederiks, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 200313A (Fermi-GBM detection: The Fermi GBM team, GCN Circ. 27374; Lesage and C. Meegan, GCN Circ. 27383; BALROG localization: Biltzinger et al., GCN Circ. 27377; IPN triangulation: Hurley et al., GCN Circ. 27385) triggered Konus-Wind at T0=6098.088 s UT (01:41:38.088). The burst light curve shows a multipeaked structure which starts at ~T0-0.4 s and has a total duration of ~43 s. The emission is seen up to ~6 MeV. As observed by Konus-Wind, the burst had a fluence of 1.46(-0.14,+0.15)x10^-4 erg/cm2, and a 64-ms peak flux, measured from T0+2.528 s, of 3.42(-0.52,+0.53)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+45.824 s) is best fit in the 20 keV - 6 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.88(-0.10,+0.12), the high energy photon index beta = -2.07(-0.17,+0.12), the peak energy Ep = 442(-66,+77) keV (chi2 = 70/75 dof). The spectrum near the maximum count rate (measured from T0+2.048 to T0+3.072 s) is best fit in the 20 keV - 6 MeV range by the GRB (Band) model with the following parameters: the low-energy photon index alpha = -0.69(-0.13,+0.17), the high energy photon index beta = -2.24(-0.21,+0.16), the peak energy Ep = 424(-69,+70) keV (chi2 = 61/58 dof). The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB200313_T06098/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.