This artist's concept shows the smallest star known to host a planet. The
planet, called VB 10b, was discovered using astrometry, a method in which
the wobble induced by a planet on its star is measured precisely on the
sky.
The dim, red star, called VB 10, is a so-called M-dwarf, located 20
light-years away in the constellation Aquila. It has only one-twelfth the
mass, and one-tenth the size, of our sun. The planet is a gas giant
similar in size to Jupiter but with six times the mass. Though the planet
is less massive than its star, the two orbs would have a similar diameter.
VB 10b orbits its star about every 9 months at a distance of 50 million
kilometers (30 million miles).