{
  "bibcode": "2014GCN.16797....1C",
  "body": "A.J. Castro-Tirado (IAA-CSIC/ISA-UMA), J. Gorosabel (IAA-CSIC/UPV-EHU) and\nA. Garcia-Rodriguez (GTC-IAC), report on behalf of a larger collaboration:\n\nWe observed the optical afterglow of GRB 140907A (Krimm et al. GCN 16788;\nKuin et al. GCN 16791; Masi et al. GCN 16792, Kuroda et al. GCN 16793)\nwith the 10.4m GTC (+OSIRIS). Spectroscopic observations started at\n05:29:33 UT (13.4 hours post GRB). Two 500s spectra were obtained with the\nR1000B and R1000R grisms, covering the range between 3800 and 9900 A, at a\nresolution of ~1000. A preliminary reduction based on archival calibration\nlamps, reveals the Mg II doublet plus several Fe II lines at a common\nredshift of z = 1.21, which we identify as the redshift of the GRB.",
  "circularId": 16797,
  "createdOn": 1410163267000,
  "email": "ajct@iaa.es",
  "subject": "GRB 140907A: redshift from the 10.4m GTC telescope",
  "submitter": "Alberto Castro-Tirado at Inst.de Astro. de Andalucia  <ajct@iaa.es>",
  "eventId": "GRB 140907A"
}