GCN Circular 26344
Subject
Konus-Wind observation of GRB191202A
Date
2019-12-05T16:23:17Z (5 years ago)
From
Anastasia Tsvetkova at Ioffe Institute <tsvetkova@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 GRB191202A (AstroSat CZTI detection: Gaikwad et al.,
GCN 26326;
Fermi GBM observation: Veres & Meegan, GCN 26329;
Fermi-LAT detection: Kocevski et al., GCN 26330)
triggered Konus-Wind at T0=74930.521 s UT (20:48:50.521).
The burst light curve shows a multi-peaked structure
which starts at ~T0-3.9 s and has a total duration of~17.6 s.
The emission is seen up to ~1.3 MeV.
As observed by Konus-Wind, the burst
had a fluence of 2.78(-0.68,+0.76)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+7.024 s,
of 8.80(-2.80,+3.04)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst
(measured from T0 to T0+15.872 s)
is best fit in the 20 keV - 1.3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.22(-0.12,+0.22),
the high energy photon index beta = -2.17(-1.00,+0.26),
the peak energy Ep = 265(-87,+91) keV,
chi2 = 46/59 dof.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB191202_T74930/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.