TITLE:   GCN CIRCULAR
NUMBER:  21088
SUBJECT: LIGO/Virgo G284239: Konus-Wind observations
DATE:    17/05/11 08:23:11 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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 G284239 (2017-05-02 22:26:07.910 UTC, hereafter T0; LIGO/VIRGO
Collaboration GCN Circ. 21060).

No triggered KW event happened from ~6 days before to ~2 days
after T0. The closest waiting-mode events are ~35 hours before and
~28 hours after 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 8.8x10^-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 3.3x10^-7 erg/cm^2/s (10 keV - 10 MeV, 2.944 s scale).

All the quoted values are preliminary.