GCN Circular 20354
Subject
GRB 161229A: POLAR observation
Date
2017-01-02T08:06:27Z (8 years ago)
From
Zhao Yi at POLAR <yizhao@ihep.ac.cn>
Yi Zhao (IHEP), Jianchao Sun (IHEP) and Yuanhao Wang (IHEP)
report on behalf of the POLAR collaboration:
At 2016-12-29T21:03:49.00 UT (T0), during a routine on-ground
search of data, POLAR detected the GRB 161229A,
which was also detected by the Fermi/GBM (trigger 504738232/161229877).
The POLAR light curve consists of multiple peaks,
with a duration (T90) of 35.77 s measured from T0+0.39 s.
The 1-s peak rate measured from T0+30.00 s is 2307.8 cnts/s,
The total counts is about 35134 cnts.The above measurements
are in the energy range of about 80-500 keV.
LC_URL:
http://polar.ihep.ac.cn/grb/2016/GRB161229A/lc/POLAR_lc_grb161229877.jpg
Using the best location from the Fermi/GBM, which is (J2000):
RA: 81.030 [deg]
Dec: +6.310 [deg]
Err: 1.00 [deg]
the incident angle in POLAR coordinate at T0 is:
theta: 87.6 [deg]
phi: -103.7 [deg]
The Minimum Detectable Polarization (MDP) for this burst is estimated
to be ~46% [3-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/.