GCN Circular 20719
Minzi Feng (IHEP), Yi Zhao (IHEP), Yuanhao Wang (IHEP) report on behalf of the POLAR collaboration: At 2017-02-19T00:03:07.00 UT (T0), during a routine on-ground search of data, POLAR detected the GRB 170219A, which was also detected by the Fermi/GBM (trigger 509155392/170219002, Circ 20706), CALET/GBM (Cherry et al. 2017, GCN 20710) INTEGRAL/SPIACS (trigger 7701), Konus-Wind (Frederiks et al. 2017, GCN 20703) and for which a triangulated position was reported by IPN (Svinkin et al. 2017, GCN 20702). The POLAR light curve consists of a single peak, with a duration (T90) of 0.15 s measured from T0+0.08 s. The 10-ms peak rate measured from T0+0.12 s is 16148.3 cnts/s. The total counts is about 964 cnts. LC_URL: http://polar.ihep.ac.cn/grb/2017/02/GRB170219A/lc/POLAR_lc_grb170219A.png The above results are not dead time corrected. The above measurements are in the energy range of about 20-500 keV. Using the best location from the Fermi/GBM, which is (J2000): RA: 72.730 [deg] Dec: +49.980 [deg] Err: 2.88 [deg] the incident angle in POLAR coordinate at T0 is: theta: 59.8 [deg] phi: -90.2 [deg] 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/.