TITLE: GCN CIRCULAR NUMBER: 20934 SUBJECT: GRB 170320A: POLAR Observation DATE: 17/03/23 06:15:20 GMT FROM: Zhao Yi at POLAR Yi Zhao (IHEP), Yuanhao Wang (IHEP), Zhengheng Li (IHEP) report on behalf of the POLAR collaboration: At 2017-03-20T03:42:39.00 UT (T0), during a routine on-ground search of data, POLAR detected the GRB 170320A, which was also detected by INTEGRAL/SPIACS (ID 170320.15474) and the KONUS-Wind. The POLAR light curve consists of a single peak, with a duration (T90) of 5.74 s measured from T0+2.79 s. The 1-s peak rate measured from T0+3.00 s is 2258.1 cnts/s. The total counts is about 5844 cnts. LC_URL: http://polar.ihep.ac.cn/grb/2017/03/GRB170320A/lc/POLAR_lc_grb170320A.png The above results are not dead time corrected. The above measurements are in the energy range of about 80-500 keV. 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/.