GCN Circular 9647

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
P. Oleynik, M. Ulanov, and D. Svinkin on behalf of
the Konus-Wind and Konus-RF teams, and
T. Cline on behalf of the Konus-Wind team, report:

The long GRB 090709A (Morris et al., GCN 9625
Not found
 
 
)
triggered Konus-Wind
at T0=27514.965 s UT (07:38:34.965),
and Konus-RF instrument onboard CORONAS-PHOTON s/c
at T0(KRF)=27513.934 s UT (07:38:33.934).

The burst light curve shows a multi-peaked structure
with a duration of ~100 s. We confirm presence of
quasi-period in the light curve (Markwardt et al., GCN 9645
Not found
 
 
).
The corresponding peaks in the FFT power spectrum
of 128 ms light curve are clearly seen around
P=8.28s (0.1208 Hz) and P=16.56s (0.0604 Hz).

The Konus-Wind light curves of this GRB are vailable
at http://www.ioffe.ru/LEA/GRBs/GRB090709_T27514/

The normalized power spectrum of the detrended
Konus-Wind light curve (128 ms, in 20-1150 keV range)
is available at
http://www.ioffe.ru/LEA/GRBs/GRB090709_T27514/GRB090709_T27514_KW_power.png

As observed by Konus-Wind the burst had
a fluence of (9.1 � 0.07)x10-5 erg/cm2,
and a 256-ms peak flux measured from T0+23.308 s
of (3.9 � 0.6)x10-6 erg/cm2/s
(both in the 20 keV - 3 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+102.912 s) is well fitted
(in the 20 keV - 3 MeV range) by GRB (Band) model
for which:
the low-energy photon index alpha = -0.85 � 0.08,
the high-energy photon index beta = -2.7(-0.3, +0.2),
the peak energy Ep = 298 � 27 keV (chi2 = 71/67 dof).

The spectrum at the maximum count rate,
measured from T0+16.640 to T0+24.320 s, is well fitted
(in the 20 keV - 3 MeV range) by GRB (Band) model
for which:
the low-energy photon index alpha = -0.86 (-0.07, +0.10),
the high-energy photon index beta = -2.6(-2.6, +0.53),
the peak energy Ep = 416(-100, +95) keV (chi2 = 63/67 dof).

All the quoted values are preliminary.
The quoted errors are at the 90% confidence level.