GCN Circular 44998
Subject
Konus-Wind detection of GRB 260617A
Event
Date
2026-06-19T12:29:15Z (14 days ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
Via
Web form
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The short-duration GRB 260617A
(Fermi-GBM detection: Fermi GBM team, GCN 44969;
Godwin & Meegan, GCN 44972;
IPN triangulation: Kozyrev et al., GCN 44982;
CALET-GBM detection: Torii et al., GCN 44989)
triggered Konus-Wind at T0=77808.934 s UT (21:36:48.934).
The burst light curve shows a multi-peaked pulse,
which starts at ~T0-64 ms and has a total duration of ~150 ms.
The emission is seen up to ~4 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB260617_T77808/
As observed by Konus-Wind, the burst
had the total fluence of 1.28(-0.16,+0.19)x10^-6 erg/cm2,
and the 16-ms peak flux, measured from T0-0.060 s,
of 1.73(-0.36,+0.38)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
Since the brightest peak of the burst light curve
was detected before the trigger, the spectral analysis
was performed using the KW 3-channel light curve data.
Modelling the KW 3-channel time-integrated spectrum
(measured from T0-0.064 s to T0+0.084 s)
by a power law with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -0.26(-0.32,+0.40) and Ep = 537(-85,+129) keV.
All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.