TITLE:   GCN CIRCULAR
NUMBER:  37172
SUBJECT: Konus-Wind detection of GRB 240810A
DATE:    24/08/13 10:09:19 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 short-duration GRB 240810A
(Fermi-GBM detection: The Fermi GBM team, GCN 37133;
IPN triangulation: Kozyrev et al., GCN 37156;
SVOM-GRM observation: Sun et al., GCN 37166)
triggered Konus-Wind at T0=76037.735 s UT (21:07:17.735).

The burst light curve shows two separated emission episodes.
The initial, hard episode starts at ~T0-0.048 s and has
a duration of ~0.1 s. The second, softer episode
starts at ~T0+0.768 s and ends at ~T0+1.2 s.
The total burst duration is ~1.25 s.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240810_T76037/

As observed by Konus-Wind, the burst
had a fluence of 1.10(-0.09,+0.42)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.032 s,
of 9.59(-1.77,+3.95)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the brightest peak of the burst light curve
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 T0-0.048 s to T0+1.200 s)
by a power law with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -0.90(-0.21,+0.26) and Ep = 383(-99,+165) keV.

Modelling the KW 3-channel spectrum near the peak count rate
(measured from T0-0.048 to T0+0.050 s)
by a power law with exponential cutoff (CPL) model
yields alpha = -0.35(-0.24,+0.26) and Ep = 546(-99,+139) keV.

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