TITLE:   GCN CIRCULAR
NUMBER:  20668
SUBJECT: Konus-Wind observation of GRB 170210A
DATE:    17/02/13 13:19:12 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

The long-duration, bright GRB 170210A
(Fermi-GBM detection: Roberts and Mailyan, GCN Circ. 20660;
IPN Triangulation: Hurley et al., GCN Circ. 20661;
POLAR detection: Wang et al., GCN Circ. 20665)
triggered Konus-Wind at T0=10092.18 s UT (02:48:12.180).

The burst light curve shows a multipeaked structure which
starts at ~T0-41 s and has a total duration of ~124 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/GRB170210_T10092/

As observed by Konus-Wind, the burst
had a fluence of 1.40(-0.16,+0.16)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+7.152 s,
of 1.83(-0.33,+0.33)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+86.528 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.99(-0.06,+0.07),
the high energy photon index beta = -2.55(-0.68,+0.26),
the peak energy Ep = 392(-40,+45) keV
(chi2 = 105/97 dof)

The spectrum near the maximum count rate
(measured from T0+5.888 to T0+7.680 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.63(-0.14,+0.17),
the high energy photon index beta = -2.30(-0.39,+0.21),
the peak energy Ep = 410(-76,+90) keV
(chi2 = 70/65 dof)

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