HD 33142 and Its Three Known Planets

HD 33142 is a star located 396 light-years away. Its spectral type is K0 III, placing it in the cooler K class, and it has an age of 2.72 billion years. Its reported mass is 1.52 solar masses, its radius is 4.17 solar radii, and its temperature is 5030 K. The star’s reported mass estimate is larger than the Sun’s, its reported radius estimate is larger than the Sun’s, and its reported temperature is cooler than the Sun’s.

Three planets are known to orbit HD 33142. All three were found 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 33142 b was discovered in 2011. Its minimum mass is 400 Earth masses, a lower bound on its true mass, and this is roughly 1.26 times Jupiter’s mass. Its orbital period is 330 days.

HD 33142 c was discovered in 2016. Its minimum mass is 283 Earth masses, and its orbital period is 810 days, the longest among the listed planets.

HD 33142 d was discovered in 2022. Its minimum mass is 63.6 Earth masses, the smallest among the listed planets, and its orbital period is 89.9 days, the shortest among the listed planets. Among the listed planets, HD 33142 b has the second-shortest year, and HD 33142 c has the second-smallest minimum mass.