Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
Introducing Einstein Probe, Astro Flavored Markdown, and Notices Schema v4.0.0. See news and announcements

GCN Circular 30403

Konus-Wind detection of GRB 210706A
2021-07-07T13:05:45Z (3 years ago)
Anna Ridnaia at Ioffe Institute <>
A. Ridnaia, D. Frederiks, S. Golenetskii, A. Lysenko,
D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration GRB 210706A
(Fermi GBM trigger 647252274;
Swift/BAT-GUANO detection: Tohuvavohu et al., GCN 30393)
triggered Konus-Wind at T0=29875.487 s UT (08:17:55.487).

The burst light curve shows a multipeaked structure
started at ~T0-2.7 s with a total duration of ~8.9 s.
The emission is seen up to ~4 MeV.

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

As observed by Konus-Wind, the burst
had a fluence of 5.39(-0.66,+0.90)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+1.040 s,
of 2.73(-0.92,+0.99)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 - 4 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.11(-0.26,+0.30)
and Ep = 263(-59,+112) keV (chi2 = 65/71 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.3
(chi2 = 65/70 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