{
  "bibcode": "2017GCN.20458....1X",
  "body": "D. Xu (NAOC/CAS), K. E. Heintz (Univ. Iceland and DARK/NBI), D. \nMalesani, J. P. U. Fynbo (DARK/NBI) report on behalf of a larger \ncollaboration:\n\nWe observed the optical afterglow of GRB 170113A (Evans et al. GCN \n20446; Veres et al., GCN 20452; Guidorzi et al., GCN 20448) with the ESO \nVery Large Telescope UT 2 (Kueyen) equipped with the X-shooter \nspectrograph, covering the wavelength range 3500-20000 AA. Spectroscopy \nstarted at 01:17:53 UT on 2017-01-14 (i.e., 15.23 hr after the GRB) and \nconsisted of 4 exposures of 1200 s each.\n\n From the acquisition image prior to the spectroscopy, the afterglow has \nm(r)~21.7 mag, calibrated with nearby USNO B1 stars.\n\nThe spectrum exhibits several absorption features such as Si II, Fe II, \nMg II, as well as emission features such as [O II] doublet, Hbeta, \n[OIII] doublet, all at a common redshift of z=1.968. We conclude this is \nthe redshift of the GRB.\n\nWe acknowledge the excellent support from the ESO staff, particularly \nLuca Sbordone, Laura Magrini, Cedric Ledoux, and Elizabeth (Liz) \nBartlett, in obtaining these observations.",
  "circularId": 20458,
  "createdOn": 1484415188000,
  "email": "dxu@nao.cas.cn",
  "subject": "GRB 170113A: VLT/X-shooter redshift",
  "submitter": "Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>",
  "eventId": "GRB 170113A"
}