[vsnet-grb-info 13740] Konus-Wind observation of GRB 130727A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15055
SUBJECT: Konus-Wind observation of GRB 130727A
DATE:    13/07/28 10:40:40 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at 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 long-duration GRB 130727A
(Swift-BAT trigger 564342: Stroh, et al., GCN 15046)
triggered Konus-Wind at T0=60324.015 s UT (16:45:24.015)

The light curve shows multiple overlapping peaks from ~T0-2 s to ~T0+12 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/GRB130727_T60324/

As observed by Konus-Wind, the burst
had a fluence of (9.0 ± 1.1)x10-6 erg/cm2,
and a 64-ms peak flux, measured from T0+0.064 s,
of (2.9 ± 0.4)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 18 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.23 ± 0.22,
the high energy photon index beta = -2.21 ± 0.12,
the peak energy Ep = 113 ± 22 keV,
chi2 = 116/97 dof.

All the quoted results are preliminary.