HD 69830: A K-Type Dwarf with Three Planets

HD 69830 is a K0V star located 41 light-years from Earth. It has a reported mass of 0.85 solar masses, a radius of 0.9 solar radii, and a temperature of 5360 K; its mass and radius estimates are smaller than the Sun's, and its temperature is cooler than the Sun's. The star's age is 9.4 billion years. Three planets are known to orbit it, all discovered in 2006 by the radial velocity method, which detects the wobble a planet's gravity induces in its star's motion.

HD 69830 b has a minimum mass of 10.2 Earth masses, a lower bound on its true mass, and an orbital period of 8.67 days. HD 69830 c has a minimum mass of 11.8 Earth masses and an orbital period of 31.6 days. HD 69830 d has a minimum mass of 18.1 Earth masses and an orbital period of 197 days. Each planet's minimum mass is larger than Earth's.

Among the listed planets, HD 69830 b has the shortest year by reported estimates, at 8.67 days, and the smallest minimum mass, at 10.2 Earth masses. HD 69830 c has the second-shortest year, at 31.6 days, and the second-smallest minimum mass, at 11.8 Earth masses. HD 69830 d has the longest year, at 197 days, and the largest minimum mass, at 18.1 Earth masses.