{
  "bibcode": "2016GCN.19419....1T",
  "body": "N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick),\nS. B. Cenko (NASA/GSFC), D. Perley (DARK), A. Cucchiara (GSFC/STScI),\nK. Roth (Gemini), K. Wiersema (U. Leicester), A. Fruchter (STScI), \nT. Laskar (NRAO/U.C. Berkeley) report on behalf of a larger collaboration:\n\nWe observed the optical counterpart of Fermi/LAT GRB 160509A\n(Levan et al. GCN 19410) with the Gemini North telescope\non Mauna Kea, beginning at 2016-05-10 13:15 UT obtaining\nboth optical spectroscopy with GMOS-N and near-IR imaging\nwith NIRI.\n\nOur spectroscopy covers a wavelength range of about 5900 AA\nto 10100 AA, and reveals a single, well detected emission line\nwhich we interpret as [OII] 3727 AA at a redshift of z=1.17 \n(provisional analysis).  Alternative possible identifications for this \nline are ruled out by the absence of other lines in the spectrum.\n\nOur infrared imaging shows the source, presumably some\ncombination of host and afterglow, to be very red with\nK(Vega)~16.6 and J(Vega)~19.7 calibrated via 2MASS stars\nin the field.  This would be consistent with a heavily dust\nextinguished event. We also note that the source is apparently\nunresolved in K-band seeing of 0.55 arcsec.\n\nWe acknowledge the excellent support of the Gemini staff,\nin particular Michael Hoenig, and kind cooperation of the\nvisiting observers, in expediting these observations.  We also\nthank Gemini Head of Science, Nancy Levenson, for approving \nthis request.",
  "circularId": 19419,
  "createdOn": 1462898595000,
  "email": "nrt3@star.le.ac.uk",
  "subject": "GRB 160509A Gemini North redshift",
  "submitter": "Nial Tanvir at U.Leicester  <nrt3@star.le.ac.uk>",
  "eventId": "GRB 160509A"
}