HD 240210 and Its Single Known Planet

HD 240210 is a K3 III star 1210 light-years away. The K-type designation places it in a cooler class than the Sun, and its reported temperature of 4300 K is cooler than the Sun's. Its reported mass estimate of 0.82 solar masses is also smaller than the Sun's. One planet is known to orbit this star.

That planet, HD 240210 b, was discovered in 2009 by the radial velocity method, which detects the wobble a planet's gravity induces in its star's motion. Its minimum mass is 1660 Earth masses, a lower bound on its true mass, and it completes an orbit every 502 days. That minimum mass is larger than Earth's and roughly 5.21 times Jupiter's mass.