TITLE: GCN CIRCULAR NUMBER: 20941 SUBJECT: GRB 170325B: POLAR Observation DATE: 17/03/29 06:04:37 GMT FROM: Wen Xing at POLAR Xing Wen (IHEP), Yi Zhao (IHEP), Yuanhao Wang (IHEP), report on behalf of the POLAR collaboration: At 2017-03-25T21:50:01.00 UT (T0), during a routine on-ground search of data, POLAR detected the GRB 170325B, which was also detected by KONUS-Wind. The POLAR light curve consists of a single peak, with a duration (T90) of 6.47 s measured from T0+2.80 s. The 500-ms peak rate measured from T0+4.50 s is 557.2 cnts/s. The total counts is about 1196 cnts. LC_URL: http://polar.ihep.ac.cn/grb/2017/03/GRB170325B/lc/POLAR_lc_grb170325B.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/.