Alf Ari: A Cool Giant Star and Its One Known Planet

Alf Ari is a star located 65.9 light-years from Earth. It is a K2III star, and its measured properties place it well above the Sun in both mass and size. Its mass is 3.13 solar masses, and its radius is 15.2 solar radii. Its temperature is 4500 K, making it cooler than the Sun.

One planet orbits Alf Ari. Named alf Ari b, it was discovered in 2010 using the radial velocity method, which detects the gravitational wobble a planet induces in its host star's motion. The planet's minimum mass is 572 Earth masses, a lower bound on its true mass, and it is roughly 1.8 times Jupiter's mass. Its orbital period is 381 days.