TITLE:   GCN CIRCULAR
NUMBER:  14285
SUBJECT: Konus-Wind observation of GRB 130310A
DATE:    13/03/11 14:14:12 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The short hard intense GRB 130310A
(Fermi-LAT detection: Guiriec et al., GCN 14282;
Fermi-GBM detection: Xiong and Chaplin, GCN 14283
IPN triangulation: Golenetskii et al., GCN 14284)
triggered Konus-Wind at T0=72588.897s UT (20:09:48.897)

The light curve shows a bright hard FRED-like structure
with a total duration of ~3 s.
The emission is seen up to 10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB130310_T72588/

As observed by Konus-Wind, the burst
had a fluence of (3.0 ± 0.3)x10-5 erg/cm2,
and a 16-ms peak flux, measured from T0+0.000s,
of (3.6 ± 0.2)x10-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.03 ± 0.05,
the high energy photon index beta = -1.85 ± 0.15,
the peak energy Ep = 855 ± 270 keV,
chi2 = 85.8/97 dof.

The spectrum at the maximum count rate (measured from T0 to T0+0.064 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.87 ± 0.13,
the high energy photon index beta = -1.62 ± 0.28,
the peak energy Ep = 2600 ± 1400 keV,
chi2 = 27.9/26 dof.

All the quoted results are preliminary.