TITLE: GCN CIRCULAR NUMBER: 21158 SUBJECT: LIGO/Virgo G268556/GW170104: Konus-Wind observations DATE: 17/05/28 15:48:23 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 G268556/GW170104 (2017-01-04 10:11:58.599 UTC, hereafter T0; LIGO/VIRGO Collaboration GCN Circ. 20364). No triggered KW event happened from ~2 day before to ~1 day after T0. The closest waiting-mode event was ~1.4 days before T0. Using waiting-mode data within the interval T0 +/- 100 s, we found no significant (> 5 sigma) excess over the background in both KW detectors on temporal scales from 2.944 s to 100 s. We estimate an upper limit (90% conf.) on the 10 keV – 10 MeV fluence to 9.2x10^-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 3.3x10^-7 erg/cm^2/s (10 keV - 10 MeV, 2.944 s scale). All the quoted values are preliminary. The information was originally included in a LVC Circular along with other results at 17/03/02 14:42:59 GMT.