GCN Circular 36504

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 240513A
(AstroSat CZTI detection: Joshi et al., GCN 36455
Not found
 
 
;
Fermi-LAT detection: Cutini et al., GCN 36462
Not found
 
 
;
Fermi-GBM observation: Bissaldi & Meegan, GCN 36479
Not found
 
 
) 
triggered Konus-Wind at T0=26527.128 s UT (07:22:07.128).

The burst light curve shows a multipeaked structure
which started at ~T0-5.3 s and had a total duration of ~7.8 s.
KW triggered on the second of two emission episodes
reported in GCN 36479
Not found
 
 
, this episode had a total duration of ~2.6 s.
The emission is seen up to ~6 MeV. 

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240513_T26527/

As observed by Konus-Wind, the burst
had a fluence of 3.42(-0.39,+2.50)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0-0.066 s,
of 5.12(-0.78,+2.09)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the brightest part of the burst emission
was detected before the trigger, the spectral analysis
was performed using the KW 3-channel light curve data.

Modelling the KW 3-channel time-integrated spectrum
(measured from T0-5.339 s to T0+2.512 s)
by a power law with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -1.00(-0.22,+0.26) and Ep = 732(-249,+745) keV.

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.