{
  "bibcode": "2013GCN.14798....1L",
  "body": "R. Lunnan, M. Drout, R. Chornock, and E. Berger (Harvard) report:\n\nWe observed the optical afterglow (Jelinek et al., GNC 14782; Xu et al., GCN \n14783; Nagayama et al., GCN 14784; Virgili et al., 14785; Masi et al., GCN \n14789; Leonini et al., GCN 14791; Sonbas et al., GCN 14797) of GRB 130606A \n(Ukwatta et al., GCN 14781) using the Blue Channel spectrograph on the 6.5-m MMT \nstarting at 04:04 UT on 7 June (7.0 hours after the BAT trigger).  We obtained \n4x1200s of spectroscopy spanning the wavelength range 7450-9350 Angs with a \nresolution of 2.1 Angstroms.\n\nWe detect a sharp cutoff in flux blueward of ~8425 Angs, consistent with \nLyman-alpha at a redshift of z=5.9, with very little transmission between 7850 \nand 8400 Angs, although some flux is present blueward of that.  Several metal \nabsorption lines are present to the red, including NV, Si II, C II, and O I at \nredshift z=5.913, confirming the GTC redshift of Castro-Tirado et al. (GCN \n14790, GCN 14796).",
  "circularId": 14798,
  "createdOn": 1370582186000,
  "email": "rchornock@cfa.harvard.edu",
  "subject": "GRB 130606A: MMT Spectroscopy",
  "submitter": "Ryan Chornock at Harvard  <rchornock@cfa.harvard.edu>",
  "eventId": "GRB 130606A"
}