TITLE:   GCN CIRCULAR
NUMBER:  21774
SUBJECT: Konus-Wind observation of GRB 170826A
DATE:    17/08/31 13:25:28 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:

The short-duration GRB 170826A
(Fermi GBM observation: Poolakkil et al., GCN Circ. 21715;
IPN Triangulation: Svinkin et al., GCN Circ. 21734)
triggered Konus-Wind at T0=31868.408 s UT (08:51:08.408).

The burst light curve shows a single pulse which starts
at ~T0-0.250 s and has a total duration of ~0.3 s.

As observed by Konus-Wind, the burst
had a fluence of 1.1(-0.2,+1.1)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.032 s,
of 1.1(-0.4,+1.2)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Modeling the KW 3-channel time-integrated spectrum
(from T0-0.248 s to T0+0.040 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.15(-0.26,+0.46) and Ep = 682(-261,+3960) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170826_T31868/

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.