{
  "bibcode": "2008GCN..7437....1F",
  "body": "R. J. Foley, D. Perley, and J. S. Bloom (UCB) on behalf of the GRAASP\ncollaboration report:\n\nWe obtained 2x1800 sec exposures of the optical afterglow (GCN 7428, 7430)\nof GRB 080319B (GCN 7427) using GMOS on the Gemini-South telescope with\nthe R831 grating.  The observations started at 20080319.35 (~2 hours after\nthe initial Swift trigger).  Initial reductions show a featureless\ncontinuum with no strong absorption systems, emission lines, or breaks.\nGiven our wavelength range of 595 - 815 nm, we can place the following\nconstraints on the redshift (in order of descending confidence):\n\n(1) The lack of a Lyman limit implies z < 5.5.\n(2) The lack of damped Lya or obvious Lya forest implies z < 3.9.\n(3) The lack of obvious Mg II absorption implies z < 1.1.\n\nFurther analysis is in progress.",
  "circularId": 7437,
  "createdOn": 1205926113000,
  "email": "rfoley@astro.berkeley.edu",
  "subject": "GRB 080319B: Gemini-South Spectroscopy",
  "submitter": "Ryan Foley at UC Berkeley  <rfoley@astro.berkeley.edu>",
  "eventId": "GRB 080319B"
}