TITLE: GCN CIRCULAR NUMBER: 20775 SUBJECT: LIGO/Virgo G275697: Konus-Wind observations DATE: 17/02/28 15:08:13 GMT FROM: Dmitry Svinkin at Ioffe Institute D. Svinkin, S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: Konus-Wind (KW) was observing the whole sky at the time of the LIGO event G275697 (2017-02-27 18:57:31.375 UTC, hereafter T0; LIGO/VIRGO Collaboration GCN Circ. 20763). No triggered KW event happened from ~5 days before to more than 10 hours after T0. We found no significant (> 5 sigma) detection on temporal scales from 2.944 s to 100 s using waiting mode data from both KW detectors S1 and S2 within the interval T0 +/- 100 s. We estimate an upper limit (90% conf.) on the 10 keV – 10 MeV fluence to 7.8x10^-7 erg/cm^2 for a burst lasting less than 2.944 s and having a typical KW short GRB spectrum (an exponentially cut off power law with alpha =-0.5 and Ep=500 keV). For a typical long GRB spectrum (the Band function with alpha=-1, beta=-2.5, and Ep=300 keV), the corresponding limiting peak flux is 2.7x10^-7 erg/cm^2/s (10 keV - 10 MeV, 2.944 s scale). All the quoted values are preliminary.