GCN Circular 44461

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

The long-duration GRB 260411C
triggered Konus-Wind at T0=21236.871 s UT (05:53:56.871).

The burst light curve shows a single pulse
which starts at ~T0-14.9 s and has a total duration of ~24.3 s.
The emission is seen up to ~1 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB260411_T21236/

As observed by Konus-Wind, the burst
had the total fluence of 1.31(-0.08,+0.08)x10^-5 erg/cm2,
and the 64-ms peak flux, measured from T0+1.584 s,
of 7.72(-0.94,+0.93)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 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 = -1.54(-0.09,+0.08),
the high energy photon index beta = -3.23(-6.77,+0.37),
the peak energy Ep = 105(-6,+8) keV
(chi2 = 85/81 dof).

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.