TITLE:   GCN CIRCULAR
NUMBER:  35079
SUBJECT: Konus-Wind detection of GRB 231117A (short/hard)
DATE:    23/11/17 14:21:53 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia,
Yu. Temiraev, A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The bright, short-duration GRB 231117A
(Swift-BAT detection: Laha et al., GCN Circ. 35071;
AstroSat-CZTI detection: Navaneeth et al., GCN Circ. 35072;
AGILE-MCAL detection: Cattaneo et al., GCN Circ. 35075)
triggered Konus-Wind at T0=10998.926 s UT (03:03:18.926).

The burst light curve shows a single pulse
which starts at ~T0 and has a total duration of ~0.7 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB231117_T10998/

As observed by Konus-Wind, the burst
had a fluence of 9.10(-0.94,+0.97)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.052 s,
of 5.88(-1.01,+1.03)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.15(-0.11,+0.13),
the high energy photon index beta = -2.81(-7.19,+0.43),
the peak energy Ep = 400(-82,+89) keV
(chi2 = 45/51 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.