{
  "bibcode": "2017GCN.20418....1M",
  "body": "R. Marcinkowski (PSI), H. Xiao (PSI) and W. Hajdas (PSI) report on behalf \nof the POLAR collaboration:\n\nAt 2017-01-09 03:17:35 UT(T0), during a routine on-ground search of data, \nPOLAR detected the GRB 170109A, which was also observed by Fermi GBM \n(trigger # 505624660). Significant detection was recorded in 5 of 25 \nPOLAR detection modules.\n\nThe POLAR light curve consists of multipeak structure compatible with Fermi \nGBM with duration (T90) of 9.0 +/- 1.0 s measured from T0. The 1.0 s peak \nflux at T0 + 4.5 s  is equal to 530 +/- 60 counts/sec. POLAR (5 modules) \nrecorded 3140 +/- 140 events from the burst.\n\nAbove measurements are in the energy range of about 80 - 500 keV.\n\nLC_URL: http://polar.psi.ch/triggers/GRB_170109A_raw_5of25.png\n     or http://polar.psi.ch/pub/lc.php?event=GRB+170109A\n\nUsing the best location from the Fermi GBM, which is (J2000):\n\nRA : 114.4  [deg]\nDec:  -6.8  [deg]\nErr:   2.85 [deg]\n\nthe incident angle in the POLAR coordinate at T0 is:\nTheta: 81.0 [deg]\nPhi:  114.3 [deg]\n\nThe analysis results presented above are preliminary. Calibration of the \ninstrument is ongoing. POLAR is a dedicated Gamma-Ray Burst polarimeter \nwhich was launched on-board the Chinese space laboratory Tiangong-2 (TG-2) \non Sep 15, 2016. The energy detection range of POLAR is ~ 50-500 keV.\nMore information about POLAR can be found at http://polar.psi.ch/pub , \nhttp://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .\n\nThis message is quotable in publications.",
  "circularId": 20418,
  "createdOn": 1484062224000,
  "email": "radoslaw.marcinkowski@psi.ch",
  "subject": "GRB 170109A: POLAR Observation",
  "submitter": "Radek Marcinkowski at PSI/POLAR  <radoslaw.marcinkowski@psi.ch>",
  "eventId": "GRB 170109A"
}