Tau Bootis hosts both a "hot Jupiter" planet and a much more
distant binary companion. The circle shows the location of the
class F star Tau Bootis (in the constellation Bootes). The
planet, which has a mass at least 3.87 times that of Jupiter,
has one of the shortest known periods, only 3.31 days, and
orbits at a close distance of 0.046 astronomical units from the
star (6.9 million kilometers, 12 percent Mercury's distance from
the Sun) in a nearly circular orbit, making it one of the
several "hot Jupiter's known. The planet, while not actually
seen, may have been detected in light reflected from the central
star.