TITLE: GCN CIRCULAR NUMBER: 25313 SUBJECT: Konus-Wind observation of GRB 190810A DATE: 19/08/12 11:39:06 GMT FROM: Anna Kozlova at Ioffe Institute A. Kozlova, 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 short-duration GRB 190810A (IPN triangulation: Hurley et al., GCN 25312) triggered Konus-Wind at T0=58318.421 s UT (16:11:58.421). The burst light curve shows a single pulse which starts at T0-0.1 s and has a total duration of ~0.2 s. As observed by Konus-Wind, the burst had a fluence of 2.29(-0.40,+0.85)x10^-6 erg/cm2, and a 16-ms peak flux, measured from T0-0.042 s, of 2.23(-0.55,+0.92)x10^-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). Since the most intense part of the burst was detected before the trigger, the spectral analysis was performed using the KW 3-channel light curve data. Modeling the KW 3-channel time-integrated spectrum (from T0-0.098 s to T0+0.088 s) by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) yields alpha = -0.61 (-0.22,+0.27), and Ep = 1120 (-266,+656) keV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB190810_T58321/ All the quoted errors are at the 68% confidence level. All the quoted values are preliminary.