{
  "bibcode": "2016GCN.20126....1X",
  "body": "S. L. Xiong (IHEP), N. Produit (UniGe), T. W. Bao (IHEP), T. Batsch (NCBJ),\nT. Bernasconi, F. Cadoux, I. Cernuda (UniGe), J. Y. Chai, Y. W. Dong, M.  Z. Feng (IHEP),\nN. Gauvin (UniGe), M. Y. Ge (IHEP), W. Hajdas (PSI), J. J. He, Y. Huang (IHEP),\nM. R. Kole (UniGe), M. N. Kong (IHEP), C. Lechanoine-Leluc (UniGe), H.  C. Li,\nL. Li, Z. H. Li, J. T. Liu, X. Liu, F. J. Lu (IHEP), R. Marcinkowski (PSI), S. Orsi, M. Pohl,\nD. Rapin (UniGe), A. Rutczynska, D. Rybka (NCBJ), H. L. Shi, L. M. Song, J. C. Sun (IHEP),\nJ. Szabelski (NCBJ), R. J. Wang, Y. H. Wang, X. Wen, B. B. Wu (IHEP), X.  Wu (UniGe),\nH. L. Xiao (PSI), H. H. Xu, M. Xu, J. Zhang, L. Zhang, L. Y. Zhang (IHEP), P. Zhang (PSI),\nS. N. Zhang, X. F. Zhang, Y. J. Zhang, Y. Zhao, S. J. Zheng (IHEP), A. \nZwolinska (NCBJ)\n(i.e. the POLAR team):\n\nPOLAR, a dedicated Gamma-Ray Burst polarimeter, has been launched successfully\non-board the Chinese space laboratory Tiangong-2 (TG-2) on Sep 15, 2016.\n\nDuring the commissioning operation phase, at 19:48:05.00 UT on 28 \nSeptember 2016 (T0),\nPOLAR detected the GRB160928A in a routine ground search of the data,\nwhich was also observed by the Fermi/GBM (trigger 496784887/160928825),\nINTEGRAL/SPI-ACS (trigger #7579) and Konus-WIND (trig #4385).\n\nPOLAR can localize bursts within its FOV (~ half sky) to an accuracy of degrees\n(Suarez-Garcia et al., NIM A, 2010, 624). However, since this burst is \nnot very bright and\nfalls on the edge of the FOV, the localization is difficult and still on-going.\n\nUsing the best location from the Fermi/GBM, which is (J2000):\nRA:   130.39    [deg]\nDec:    8.14    [deg]\nErr:    3.19    [deg]\n\nthe incident angle at T0 in POLAR detector coordinate is:\ntheta:   94.7   [deg]\nphi:    -26.8   [deg]\n\nThe distribution of the GRB signal among its 25 detector modules is \nconsistent with this incident geometry.\n\nIn addition, the timing and structures in the POLAR light curve is well \nconsistent with that of other instruments mentioned above.\nThus we conclude that this event is the first confirmed GRB which POLAR detected,\nand that POLAR works as expected.\n\nThe POLAR light curve consists of multiple peaks\nwith a duration (T90) of 5.1 s measured from T0-1.7 s.\nThe 50-ms peak flux, measured from T0+0.55 s, is 1406.7 cnts/sec.\nThe above measurements are in the energy range of about 80-500 keV.\n\nThe analysis results presented above are preliminary;\nfinal results will be published in the POLAR paper.\n\nThe POLAR mission is a joint effort of the international collaboration \nbetween the Institute of High Energy Physics (IHEP) in China, the University of \nGeneva (UniGe) and the Paul Scherrer Institute (PSI) in Switzerland, and the National \nCenter for Nuclear Research (NCBJ) in Poland. More information about POLAR could be \nfound at http://polar.ihep.ac.cn/en/.\n\n[GCN OPS NOTE(05nov16):  Per author's request, the affiliation in the FROM:-line\nwas changed from \"POLAR\" to \"IHEP\".  And some line-wrapping was fixed.",
  "circularId": 20126,
  "createdOn": 1478273406000,
  "email": "xiongsl@ihep.ac.cn",
  "subject": "GRB 160928A: The first GRB detected by POLAR",
  "submitter": "Shaolin Xiong at IHEP  <xiongsl@ihep.ac.cn>",
  "eventId": "GRB 160928A"
}