GCN Circular 20665
Subject
GRB 170210A: POLAR observation
Date
2017-02-12T02:55:11Z (8 years ago)
From
Yuanhao Wang at IHEP/CAS <wangyuanhao@ihep.ac.cn>
Y.H. Wang (IHEP), M.Z. Feng (IHEP), Y. Zhao (IHEP),
report on behalf of the POLAR collaboration:
At 2017-02-10T02:47:37 UT (T0), during a routine on-ground
search of data, POLAR detected the long-duration GRB 170210A,
which was also reported by the
Fermi/GBM (O.J. Roberts et al, GCN Circ. 20660) and
IPN Triangulation(K. Hurley et al, GCN Circ. 20661), and also
detected by Konus-Wind.
The POLAR light curve shows a long burst consists of multiple peaks,
with a duration (T90) of 62.27 s measured from T0+13.12 s.
The 1-s peak rate measured from T0+41.0 s is 6673.75cnts/s.
The total counts is about 106099 cnts.
LC_URL:
http://polar.ihep.ac.cn/grb/2017/02/GRB170210A/lc/POLAR_lc_grb170210A.png
The above results are not dead time corrected. The above
measurements are in the energy range of about 20-500 keV.
Using the best location from the IPN Triangulation, which is (J2000):
RA: 226.055 [deg]
Dec: -65.101 [deg]
Err: 1731 [sq. arcmin](3 sigma)
the incident angle in POLAR coordinate at T0 is:
theta: 80.6 [deg]
phi: 130.9 [deg]
The Minimum Detectable Polarization(MDP) for this burst is
estimated to be ~7.3% [1-sigma, statistical only].
All analysis results presented above are preliminary.
POLAR is a dedicated Gamma-Ray Burst polarimeter (50-500 keV)
on-board the Chinese space laboratory Tiangong-2 launched on
Sep 15,2016. More information about POLAR can be found at
http://polar.ihep.ac.cn/en/ , http://isdc.unige.ch/polar/
and http://polar.psi.ch/pub/.