{
  "bibcode": "2011GCN.12284....1D",
  "body": "P. D'Avanzo (INAF/Brera), M. Sparre, D. Watson, J. P. U. Fynbo, D. \nMalesani, B. Milvang-Jensen (DARK/NBI), P. Goldoni (APC/Univ. Paris 7 \nand SAp/CEA), V. D'Elia (INAF/Rome), and N. R. Tanvir (U. Leicester), \nreport on behalf of the X-shooter GTO GRB collaboration:\n\nWe observed the field of GRB 110818A (Markwardt et al. GCN 12279) with \nthe ESO VLT equipped with X-shooter. Observations started on 2011-08-19 \nat 02:47 UT (6.15 hr after the GRB).\n\nThe acquisition image shows an optical afterglow candidate inside the \nXRT error circle (Markwardt et al. GCN 12279) at the following \ncoordinates (J2000):\n\nRA = 21:09:21.04\nDec = -63:58:52.3\n\nwith an uncertainty of about 0.5\". The object has a magnitude R ~ 22.3, \ncalibrated assuming R = 19.2 for the USNO-B1 star 0260-0726657 (RA, Dec \n= 21:09:23.14, -63:58:33.0).\n\nA total spectroscopic exposure of 4x1200 s was obtained, covering the \nspectral range from 300 to 2500 nm.\n\nWe report a redshift of z = 3.36 based on detection of absorption \nfeatures from Si II, C IV, Al II, Ca H, Ca K and Mg I. Emission from the \n[O III] doublet is also observed.\n\nWe would like to thank the staff at the VLT, in particular, Alain \nSmette, Patricia Guajardo and Dimitri Gadotti for carrying out the \nobservations.",
  "circularId": 12284,
  "createdOn": 1313740187000,
  "email": "malesani@dark-cosmology.dk",
  "subject": "GRB 110818A: Optical afterglow and redshift from VLT/X-shooter",
  "submitter": "Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst  <malesani@dark-cosmology.dk>",
  "eventId": "GRB 110818A"
}