HD 13808 and Its Two Known Planets

HD 13808 is a K2 V star 92.1 light-years away. The star's reported mass estimate is smaller than the Sun's, its reported radius estimate is smaller than the Sun's, and its reported temperature of 5040 K is cooler than the Sun's. It is 7.2 billion years old and hosts two known planets.

Both planets were found in 2021 by the radial velocity method, which measures the wobble a planet's gravity induces in its star's motion; repeated wobbles reveal the planet and its orbital period.

HD 13808 b has a minimum mass of 11.2 Earth masses and an orbital period of 14.2 days. Among the listed planets, it has the shortest year by reported estimates (14.2 days) and the largest minimum mass (11.2 Earth masses). HD 13808 c has a minimum mass of 9.96 Earth masses and an orbital period of 53.8 days. Among the listed planets, it has the longest year by reported estimates (53.8 days) and the smallest minimum mass (9.96 Earth masses). Each minimum mass is a lower bound on the planet's true mass. Both planets' minimum masses are larger than Earth's, though neither is an ordinary mass estimate.