TITLE:   GCN CIRCULAR
NUMBER:  23939
SUBJECT: Konus-Wind observation of GRB 190305A
DATE:    19/03/07 10:21:16 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

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

The long-duration GRB 190305A
(AGILE/MCAL detection: Ursi et al., GCN Circ. 23930;
MAXI/GSC detection: Nakahira et al., GCN Circ. 23933;
Insight-HXMT/HE detection: Xiao et al., GCN Circ. 23934;
IPN Triangulation: Svinkin et al., GCN Circ. 23936)
triggered Konus-Wind at T0=47115.9 s UT (13:05:15.900).

The burst light curve shows a single pulse
started at ~T0-0.1 s with a total duration of ~11 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.47(-0.04,+0.04)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+1.024 s,
of 2.00(-0.08,+0.08)x10^-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+2.560 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 = -0.44(-0.04,+0.05),
the high energy photon index beta = -2.82(-0.11,+0.10),
the peak energy Ep = 387(-15,+16) keV
(chi2 = 130/74 dof).

The spectrum near the maximum count rate
(measured from T0+0.768 to T0+1.280 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 = -0.15(-0.07,+0.07),
the high energy photon index beta = -2.96(-0.15,+0.12),
the peak energy Ep = 422(-20,+20) keV
(chi2 = 87/59 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190305_T47118/

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