GCN Circular 23809

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

The extremely bright, long GRB 190129B
(IPN triangulation: Hurley et al., GCN 23808
Not found
 
 
)
triggered Konus-Wind (KW) at T0=44134.335 s UT (12:15:34.335).

The light curve of the burst shows a multi-peaked pulse,
which started at ~T0-10 s and had a duration of ~ 60s,
which was followed by a weaker and softer pulse around ~T0+130 s.
The emission is seen up to ~20 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190129_T44134/

As observed by Konus-Wind, the burst had
a fluence of (5.59 �� 0.40)x10^-4 erg/cm2 and
a 64-ms peak energy flux, measured from T0+17.344,
of (1.19 �� 0.04)x10^-4 erg/cm2 (both in the 20 keV - 10 MeV
energy range).

The time-integrated spectrum (measured from T0 to T0+152.832 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.85 (-0.06,+0.06),
the high energy photon index beta = -2.18 (-0.16,+0.11),
the peak energy Ep = 561 (-53,+56) keV,
chi2 = 107/97 dof.

The spectrum near the peak count rate (measured from T0+17.152 s
to T0+18.432 s) is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.64 (-0.06,+0.06),
the high energy photon index beta = -2.13 (-0.08,+0.07),
the peak energy Ep = 717 (-62,+66) keV,
chi2 = 89/77 dof.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.