TITLE:   GCN CIRCULAR
NUMBER:  28652
SUBJECT: Konus-Wind observation of GRB 201013A
DATE:    20/10/16 13:12:24 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The long-duration, bright GRB201013A
(Swift/BAT detection: Page  et al., GCN 28607; Laha et la., GCN 28614;
CALET Gamma-Ray Burst Monitor detection: Tamura et al., GCN 28618;
AstroSat CZTI detection: Gupta et al., GCN 28620;
Insight-HXMT/HE detection: Zheng et al.,  GCN 28625)
triggered Konus-Wind at T0=13589.476 s UT (03:46:29.476).

The burst light curve shows a double-peaked structure
which starts at ~T0-0.2 s and has a total duration of~11.4 s
The emission is seen up to ~3 MeV.

As observed by Konus-Wind, the burst
had a fluence of 2.77(-0.33,+0.37)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+0.768 s,
of 1.64(-0.26,+0.27)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+9.216 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.79(-0.13,+0.17),
the high energy photon index beta = -2.24(-0.21,+0.15),
the peak energy Ep = 212(-31,+32) keV,
chi2 = 73/65 dof.

The spectrum near the peak count rate
(measured from T0 to T0+1.024 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.49(-0.14,+0.16),
the high energy photon index beta = -2.50(-0.35,+0.20),
the peak energy Ep = 308(-39,+46) keV,
chi2 = 75/57 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB201013_T13589/

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