//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 20311 SUBJECT: GRB 161217C: POLAR observation DATE: 16/12/21 01:26:37 GMT FROM: Yuanhao Wang at IHEP/CAS Y. H. Wang (IHEP/CAS), S. L. Xiong(IHEP/CAS) report for the POLAR collaboration: At 2016-12-17T03:53:15 UT (T0), during a routine on-ground search of data, POLAR detected the GRB 161217C, which was also detected by the IPN-KW. The POLAR light curve consists of two peaks, with a duration (T90) of 6.409 s measured from T0-2.8525 s. The 0.5s peak rate measured from T0+3.0s is 1733 cnts/s, The total counts is about 4364 cnts.  The above measurements are in the energy range of about 80-500 keV. LC_URL: http://polar.ihep.ac.cn/grb/2016/GRB161217C/lc/POLAR_lc_grb161217161.png All the analysis results presented above are preliminary. Calibration of the instrument is ongoing. 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/ .