GCN Circular 20310

J.C. Sun (IHEP/CAS), Y.H. Wang (IHEP/CAS), H.C. Li (IHEP/CAS) and

S.L. Xiong (IHEP/CAS) report on behalf of the POLAR collaboration:




At 2016-12-17T03:03:44.00 UT(T0), during a routine on-ground search

of data, POLAR detected the GRB 161217B, which was also observed

by Fermi-GBM (trigger #503636629).




The POLAR light curve consists of a single peak with a duration (T90)

of 5.317 s measured from T0-0.68 s. The 500-ms peak rate measured at

T0+0.25 s is 204.4 cnts/sec. The above measurements are in the energy

range between about 80 �C 500 keV.




LC_URL:

http://polar.ihep.ac.cn/grb/2016/GRB161217B/lc/POLAR_lc_grb161217128.png




Using the best location from the Fermi/GBM, which is (J2000):

RA:   216.630   [deg]

Dec:  +51.980   [deg]

Err:  7.56      [deg]




the incident angle in POLAR coordinate at T0 is:

theta:  53.974  [deg]

phi:    30.943  [deg]




The analysis results presented above are preliminary. Calibration of the

instrument is ongoing.




POLAR is a dedicated Gamma-Ray Burst polarimeter which was launched

on-board the Chinese space laboratory Tiangong-2 (TG-2) on Sep 15, 2016.

The energy detection range of POLAR is ~ 50-500 keV. 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/ .




This message is quotable in publications.