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.