HD 29399 and Its Planet

HD 29399 is a K1 III star 144 light-years away. The system holds one known planet. The star is 6.2 billion years old, with a mass of 1.17 solar masses and a radius of 4.5 solar radii. Its temperature is 4850 K. The reported mass estimate is larger than the Sun's, as is the reported radius estimate; the reported temperature is cooler than the Sun's. A spectral type of K1 III places the star in the K class, cooler than the Sun's G class.

The planet HD 29399 b was found in 2022 using the radial velocity method, which measures the wobble a planet's gravity induces in its star's motion. Its orbital period is 893 days. Its minimum mass is 499 Earth masses, meaning its true mass is at least this much; this is roughly 1.57 times Jupiter's mass and larger than Earth's.