[vsnet-grb-info 24514] Konus-Wind observation of GRB 191227B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26613
SUBJECT: Konus-Wind observation of GRB 191227B
DATE:    19/12/30 12:56:09 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin at mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline
on behalf of the Konus-Wind team, report:

The short-duration GRB 191227B
(IPN triangulation: Hurley et al., GCN Circ. 26612)
triggered Konus-Wind at T0=62500.487 s UT (17:21:40.487).

The burst light curve shows a multi-peaked structure
which starts at ~T0 s and has a total duration of ~0.2 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/GRB191227_T62500/

As observed by Konus-Wind, the burst
had a fluence of 8.80(-1.42,+1.40)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.030 s,
of 8.83(-2.12,+2.10)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+0.192 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.56(-0.21,+0.31),
the high energy photon index beta = -2.35(-1.19,+0.38),
the peak energy Ep = 985(-323,+373) keV
(chi2 = 49/49 dof).

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