GCN Circular 42473
Subject
Konus-Wind detection of GRB 251016A (short/hard)
Event
Date
2025-10-27T12:47:24Z (2 months ago)
From
Valentina Panteleeva at Ioffe Institute <panteleevav228@gmail.com>
Via
Web form
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 short-duration GRB 251016A
(SVOM/ECLAIRs detection: Basa et al., GCN 42308;
Brunet et al., GCN 42374;
Fermi-GBM detection: The Fermi GBM team, GCN 42309;
Smith and Meegan, GCN 42365;
Glowbug detection: Woolf et al., GCN 42313;
CALET-GBM detection: Kawakubo et al., GCN 42321;
AstroSat-CZTI detection: Arya et al., GCN 42327;
Insight-HXMT/HE detection: Zao et al., GCN 42359)
triggered Konus-Wind at T0=53956.564 s UT (14:59:16.564).
The burst light curve shows a single pulse
which starts at ~T0-0.2 s and has a total duration of ~0.5 s.
The emission is seen up to ~3 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB251016_T53956/
As observed by Konus-Wind, the burst
had the total fluence of 6.32(-0.91,+1.04)x10^-6 erg/cm2,
and the 16-ms peak flux, measured from T0+0.018 s,
of 2.46(-0.52,+0.58)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+0.256 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(-0.20,+0.35),
the high energy photon index beta = -2.14(-0.72,+0.34),
the peak energy Ep = 825(-282,+293) keV
(chi2 = 30/25 dof).
All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.