Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 33586

Konus-Wind detection of GRB 230405B
2023-04-07T11:34:01Z (a year ago)
Anna Ridnaia at Ioffe Institute <>
A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 230405B
(Fermi-GBM detection: The Fermi GBM team, GCN 33570;
Wood & Meegan, GCN 33583;
Swift-BAT detection: Page et al., GCN 33571;
AstroSat CZTI detection: Navaneeth et al., GCN 33575;
AGILE detection: Casentini et al., GCN 33585)
triggered Konus-Wind at T0=71884.77 s UT (19:58:04.770).

The burst light curve shows a single pulse,
which starts at ~T0-6.1 s and has a total duration of ~10.7 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at

As observed by Konus-Wind, the burst
had a fluence of 2.24(-0.23,+0.27)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+1.088 s,
of 9.76(-1.97,+2.26)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 = -0.37(-0.26,+0.30),
the high energy photon index beta = -2.75(-0.64,+0.31),
the peak energy Ep = 184(-20,+23) keV
(chi2 = 101/91 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
Looking for U.S. government information and services? Visit