{
  "bibcode": "2017GCN.20501....1X",
  "body": "H.L. Xiao (PSI) , W. Hajdas (PSI) and R. Marcinkowski (PSI) report on behalf of the POLAR collaboration:\n\nAt 2017-01-21 01:36:55.20 UT(T0), during a routine on-ground search of data, POLAR detected the GRB 170121A,\nwhich was also observed by Fermi GBM (trigger #506655418) .\n\nThe POLAR light curve consists of one peak with duration (T90) of 3.25 +/- 0.25 s measured from T0.\nThe 0.25 s peak flux at T0 + 0.75 s  is equal to 3000 +/- 100 counts/sec.\nPOLAR recorded 4290 events from the burst.\nAbove measurements are in the energy range of about 80 - 500 keV.\n\nLC_URL: http://polar.psi.ch/triggers/GRB_170121A_raw.png\n     or raw LC: http://polar.psi.ch/pub/lc.php?event=GRB+170121A\n\nUsing the best location from Fermi GBM, which is (J2000):\nRA : 3.0 [deg]\nDec: -75.62 [deg]\nthe incident angle in POLAR coordinate at T0 is:\nTheta: 37.5 [deg]\nPhi: 290.8 [deg]\n\nThe analysis results presented above are preliminary. Calibration of the instrument is ongoing.\nPOLAR is a dedicated Gamma-Ray Burst polarimeter which was launched on-board the Chinese space\nlaboratory Tiangong-2 (TG-2) on 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 ,\n http://polar.ihep.ac.cn/en/ and http://isdc.unige.ch/polar/ .\n\nThis message is quotable in publications.",
  "circularId": 20501,
  "createdOn": 1485123064000,
  "email": "hualin.xiao@psi.ch",
  "subject": "GRB 170121A: POLAR Observation",
  "submitter": "Haulin Xiao at PSI/POLAR  <hualin.xiao@psi.ch>",
  "eventId": "GRB 170121A"
}