GCN Circular 44463

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 260415C
triggered Konus-Wind at T0=27659.163 s UT (07:40:59.163).

The burst light curve shows a single pulse
which starts at ~T0-2.5 s and has a total duration of ~11.3 s.
The emission is seen up to 2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB260415_T27659/

As observed by Konus-Wind, the burst
had the total fluence of 3.64(-0.42,+0.54)x10^-6 erg/cm2,
and the 64-ms peak flux, measured from T0-0.446 s,
of 1.56(-0.41,+0.45)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 = -0.06(-0.45,+0.60),
the high energy photon index beta = -2.91(-0.94,+0.36),
the peak energy Ep = 105(-11,+12) keV
(chi2 = 92/77 dof).

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