TITLE:   GCN CIRCULAR
NUMBER:  22244
SUBJECT: Konus-Wind observation of GRB 171210A
DATE:    17/12/12 12:58:30 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova@mail.ioffe.ru>

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

The long-duration GRB 171210A
(Fermi-LAT detection: Bissaldi et al., GCN 22228,
Fermi-GBM observation: Poolakkil et al., GCN 22233)
triggered Konus-Wind at T0=42556.704 s UT (11:49:16.704).

The burst light curve shows a single pulse
started at ~T0-6.1 s with a total duration of ~186.6 s.
The emission is seen up to ~10 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.15(-0.10,+0.11)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+2.816 s,
of 7.85(-1.73,+1.79)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+140.544 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 = -0.76(-0.13,+0.15),
the high energy photon index beta = -2.42(-0.21,+0.14),
the peak energy Ep = 158(-14,+16) keV
(chi2 = 99/88 dof)

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+5.376 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 = -0.64(-0.09,+0.11),
the high energy photon index beta = -2.83(-1.36,+0.40),
the peak energy Ep = 426(-46,+46) keV
(chi2 = 70/79 dof)

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171210_T42556/

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