GCN Circular 36677

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 GRB 240615A (The Fermi GBM team, GCN 36671
Not found
 
 
;
Swift/BAT-GUANO arcminute localization: DeLaunay et al., GCN 36672
Not found
 
 
).
triggered Konus-Wind (KW) at T0=64306.225 s UT (17:51:46.225).

The burst light curve shows a single pulse,
which starts at ~T0-0.02 s and has a duration of ~0.1 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240615_T64306/

As observed by Konus-Wind, the burst had the total fluence
of 1.85(-0.49,+0.65)x10^-6 erg/cm^2 and a 16-ms peak energy flux,
measured from T0, of 3.21(-0.89,+1.15)x10^-5 erg/cm^2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst (measured from T0 to T0+0.128 s)
is best fit in the 20 keV - 15 MeV range by a power law with exponential
cutoff (CPL) model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.55(-0.27,+0.37) and Ep = 878(-281,+441) keV (chi2 = 24.4/28 dof).
Fitting this spectrum by a Band function yields the same values of alpha and Ep,
and an upper limit on the high energy photon index beta of -2.15 (chi2 = 24.5/27 dof).

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