TITLE:   GCN CIRCULAR
NUMBER:  15225
SUBJECT: Konus-Wind observation of GRB 130912A
DATE:    13/09/13 13:20:09 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred@mail.ioffe.ru>

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

The short-duration GRB 130812A (Swift-BAT trigger 570465:
D'Elia et al. GCN 15212, Krimm et al. GCN 15216;
Fermi-GBM detection: Zhang et al. GCN 15219)
triggered Konus-Wind at T0=30902.290 s UT (08:35:02.290).

The burst light curve shows two peaks in the time
interval from ~T0-0.1 s to ~T0+0.3 s.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB130912_T30902/

As observed by Konus-Wind, the burst
had a fluence of (1.6 ± 0.2)x10-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.032,
of (2.2 ± 0.6)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The 3-channel time-integrated spectrum
(measured from T0-0.128 to T0+0.256 s)
can be modeled, in the 25 keV - 1.5 MeV range,
by the cutoff power law with the following model parameters:
the photon index alpha = -0.96 ± 0.08,
and the peak energy Ep = 580 ± 65 keV.

The 3-channel spectrum at the maximum count rate
(measured from T0-0.128 to T0+0.256 s)
can be modeled, in the 25 keV - 1.5 MeV range,
by the cutoff power law with the following model parameters:
the photon index alpha = -1.07 ± 0.12,
and the peak energy Ep = 1020 ± 320 keV.

All the quoted results are preliminary.