{
  "bibcode": "2012GCN.13730....1H",
  "body": "O. E. Hartoog (Uva, NL), D. Malesani (DARK/NBI), K. Wiersema (U. Leicester,\nUK), T. Kruehler (DARK/NBI),  S. Schulze (PUC and MCSS), A. de Ugarte\nPostigo (IAA/CSIC and DARK/NBI), V. D'Elia (INAF/Roma and ASI/ASDC), J. P.\nU. Fynbo (DARK/NBI), report on behalf of the X-shooter GRB GTO\ncollaboration:\n\nWe observed the optical counterpart of GRB 120909A (Immler et al., GCN\n13727; Haislip et al., GCN 13728; Sudilovsky et al., GCN 13729) with the\nESO VLT equipped with the X-shooter spectrograph. Observations were carried\nout starting on 2012 Sep 9.14 UT (1.7 hr after the GRB), for a total\nexposure time of 20 min, covering the wavelength range 3000-25000 AA.\n\nWe detect several absorption features, including Ly-a, FeII, NiII, SiII,\nSII, AlII, AlIII, CII, OI, CIV, ZnII all at a common redshift z = 3.93. In\nparticular, the presence of fine-structure lines (Fe II*, SiII*, OI*, OI**,\nCII*) makes the redshift securely associated to the GRB.\n\nWe acknowledge support from the VLT staff, in particular Giovanni Carraro\nand Giacomo Beccari.",
  "circularId": 13730,
  "createdOn": 1347168172000,
  "email": "O.E.Hartoog@uva.nl",
  "subject": "GRB 120909A: X-Shooter redshift 3.93",
  "submitter": "Olga Hartoog at U of Amsterdam  <O.E.Hartoog@uva.nl>",
  "eventId": "GRB 120909A"
}