{
  "bibcode": "2014GCN.16454....1P",
  "body": "D. A. Perley (Caltech), M. L. Graham, A. V. Filippenko (UC Berkeley), \nand S. B. Cenko (GSFC) report:\n\nWe acquired a single 1200-second spectrum of iPTF14bfu (Singer et al., \nGCN 16360; Perley et al., GCN 16365), the optical transient associated \nwith GRB 140606B (Burns et al., GCN 16363), using the Low Resolution \nImaging Spectrometer (LRIS) on the Keck I 10-meter telescope.  The \nobservation was conducted starting at 13:00 UT on 2014-06-24, 18.4 days \nafter the GBM trigger, and covers a wavelength range from 320-1028 \nnanometers.\n\nThe spectrum shows several broad emission features and a significant \ndecrease in flux toward both the blue and red ends.   A comparison with \nSN 1998bw* using superfit (Howell et al. 2005, ApJ 634, 1190) shows a \ngood match between the observed features and the spectrum of SN 1998bw \nnear maximum light, indicating that the transient has evolved into a \nType Ic-BL supernova.\n\n* http://www.astro.caltech.edu/~dperley/grb/140606b/140606b_98bw.png",
  "circularId": 16454,
  "createdOn": 1403673876000,
  "email": "dperley@astro.caltech.edu",
  "subject": "GRB140606B/iPTF14bfu: Keck detection of an associated supernova",
  "submitter": "Daniel Perley at Caltech  <dperley@astro.caltech.edu>",
  "eventId": "GRB 140606B"
}