In this letter we present our first high contrast NACO/SDI observations of the exoplanet host star Gl 86 and results from NACO spectroscopy .
Els et al .
( 2001 ) found a faint co-moving companion located only \sim 2 arcsec east of the exoplanet host star Gl 86 A .
Our high contrast SDI observations rule out additional stellar companions from 1 AU up to 23 AU , and are sensitive for faint T dwarf companions down to 35 M _ { Jup } .
We present evidence for orbital motion of Gl 86 B around the exoplanet host star Gl 86 A , which finally confirms that this is a bound binary system .
With the given photometry from Els et al .
( 2001 ) and the obtained NACO spectroscopy we prove that the companion Gl 86 B is a cool white dwarf with an effective temperature of 5000 \pm 500 K. This is the first confirmed white dwarf companion to an exoplanet host star and the first observational confirmation that planets survive the post main sequence evolution of a star from which they are separated by only one to two dozen AU ( giant phase and planetary nebula ) as expected from theory .