TITLE:   GCN CIRCULAR
NUMBER:  16344
SUBJECT: Konus-Wind observation of GRB 140528A
DATE:    14/05/30 13:27:09 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

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

The long-duration, moderately intense GRB 140528A (Golenetskii et al., 
GCN 16339) triggered Konus-Wind at T0=72325.953 s UT (20:05:25.953).
The burst light curve shows a multi-peaked structure with a total 
duration of ~16 s. The emission is seen up to ~3 MeV.

As observed by Konus-Wind, the burst had a fluence of 
2.4(-0.3,+0.3)x10^-5 erg/cm2, and a 64-ms peak flux, measured from 
T0+10.112 s, of 5.1(-1.3,+1.3)x10^-6 erg/cm2/s (both in the 20 keV - 10 
MeV energy range).

The time-integrated spectrum of the burst (measured from T0 to T0+16.640 
s) is best fit in the 20 keV - 5 MeV range
by a GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.59(-0.14,+0.17),
the high energy photon index beta = -2.8(-0.7,+0.3),
the peak energy Ep = 202(-20,+21) keV,
chi2 = 47/72 dof.

The spectrum near the maximum count rate (measured from T0+8.448 s to 
T0+16.640 s) is best fit in the 20 keV - 5 MeV range
by a GRB (Band) model with the following parameters:
the low-energy photon index alpha =-0.40(-0.23,+0.27),
the high energy photon index beta = -2.7(-1.1,+0.3),
the peak energy Ep = 177(-22,+27) keV,
chi2 = 60/69 dof.

The Konus-Wind light curve of this GRB is available at 
http://www.ioffe.ru/LEA/GRBs/GRB140528_T72325/

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