TITLE:   GCN CIRCULAR
NUMBER:  39284
SUBJECT: Konus-Wind detection of GRB 250207A
DATE:    25/02/11 13:50:11 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

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 250207A
(Fermi-GBM detection: Fermi GBM team, GCN 39181;
Swift-BAT detection: Ferro et al., GCN 39182; Moss et al., GCN 39245)
was detected by Konus-Wind (KW) in the waiting mode.

A Bayesian block analysis of the KW waiting mode data
reveals a >27 sigma count rate increase in the interval
from T0-7.699 s to T0+15.853 s where T0 = T0(BAT) = 01:16:07.33 UT.

The KW light curve of this burst is available at
http://www.ioffe.ru/LEA/GRBs/GRB250207A/

Modeling a time-integrated spectrum of the burst
(from T0-7.699 s to T0+15.853 s)
by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep):
yields alpha = -1.26 (-0.12, + 0.14) and Ep = 329(-64,+91) keV.

The total burst fluence is 1.04(-0.11,+0.13)x10^-5 erg/cm^2,
and the 2.944 s peak energy flux, measured from T0+4.077 s,
is 7.05(-0.98,+1.08)x10^-7 erg/cm^2.
(both in the 20 keV - 10 MeV energy range).

All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.