TITLE: GCN CIRCULAR NUMBER: 20363 SUBJECT: GRB 170102A: POLAR observation DATE: 17/01/04 08:29:33 GMT FROM: Zhao Yi at POLAR Yi Zhao (IHEP), Hancheng Li (IHEP) and Minzi Feng (IHEP) report on behalf of the POLAR collaboration: At 2017-01-02T02:51:18.00 UT (T0), during a routine on-ground search of data, POLAR detected the GRB 170102A, which was also detected by the KONUS-Wind. The POLAR light curve consists of multiple peaks, with a duration (T90) of 40.03 s measured from T0-1.66 s. The 1-s peak rate measured from T0+23.00 s is 335.7 cnts/s. The total counts is about 4727 cnts. The above measurements are in the energy range of about 80-500 keV. LC_URL: http://polar.ihep.ac.cn/grb/2017/01/GRB170102A/lc/POLAR_lc_grb170102A.jpg 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/.