  We report the detection of a planetary companion orbiting the solar-type star
HD 80606, the brighter component of a wide binary with a projected separation
of about 2000 AU. Using high-signal spectroscopic observations of the two
components of the visual binary, we show that they are nearly identical. The
planet has an orbital period of 111.8 days and a minimum mass of 3.9 M_Jup.
With e=0.927, this planet has the highest orbital eccentricity among the
extrasolar planets detected so far. We finally list several processes this
extreme eccentricity could result from.
