GCN Circular 20288
Subject
GRB 161218B: POLAR observation
Date
2016-12-18T19:04:42Z (8 years ago)
From
Yuanhao Wang at IHEP/CAS <wangyuanhao@ihep.ac.cn>
Y. H. Wang (IHEP), Z. H. Li (IHEP), S. L. Xiong (IHEP)
report for the POLAR collaboration:
At��2016-12-18T08:32:41.341��UT��(T0),��during��a��routine��on-ground��
search��of��data,��POLAR��detected the GRB 161218B,��which��was��also
detected��by��the Fermi/GBM (trigger 503742764/161218356).
The��POLAR��light��curve��consists��of��multiple��peaks,
with��a��duration��(T90) of��26.28��s��measured��from��T0+1.0��s .
The��1s��peak��rate��measured��from��T0+1.25��s��is��9849��cnts/s,
The��total��counts��is��about��29340 cnts.The��above��measurements��are
in��the��energy��range��of��about��80-500��keV.
The preliminary estimation of minimum detectable polarization(MDP)
is 36.8%[3-sigma, statistical only]. Follow-up observations are
strongly encouraged.
LC_URL:
http://polar.ihep.ac.cn/grb/2016/GRB161218B/lc/POLAR_lc_grb161218356.png
Using��the��best��location��from��the��Fermi/GBM,��which� �is��(J2000):
RA: 358.640 [deg]
Dec: -16.950 [deg]
Err: 1.00 [deg]
the��incident��angle��in��POLAR��coordinate��at��T0��is:
theta:�� 77.7612 ��[deg]
phi: ����252.239�� [deg]
The��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/html/