Six Planets Around HD 110067

HD 110067 is a K-type main-sequence star 105 light-years away. Its spectral type of K0.0 V places it in the cooler, redder part of the K class, between the Sun's G type and the redder M dwarfs. The star is 8.1 billion years old, with a mass of 0.798 solar masses, a radius of 0.788 solar radii, and a temperature of 5270 K. Its mass, radius, and temperature are all smaller or cooler than the Sun's. Six planets are known to orbit this star.

All six were discovered by the transit method in 2023. In a transit, a planet crosses in front of its star from our viewpoint, dimming it slightly; repeated dips help establish orbital periods.

HD 110067 b is a Super-Earth with a mass of 5.69 Earth masses, a radius of 2.2 Earth radii, and an orbital period of 9.11 days. Its mean density is 2.94 g/cm³, 0.534 times Earth's. Among the listed planets, it has the shortest year by reported estimates and the second-smallest radius.

HD 110067 c, also a Super-Earth, has a reported upper limit of 6.3 Earth masses, a radius of 2.39 Earth radii, and an orbital period of 13.7 days. Among the listed planets, it has the second-shortest year.

HD 110067 d is Neptune-like, with a mass of 8.52 Earth masses. Its radius of 2.85 Earth radii is the largest among the listed planets, and its orbital period is 20.5 days. Its mean density is 2.02 g/cm³, 0.367 times Earth's.

HD 110067 e is a Super-Earth with a reported upper limit of 3.9 Earth masses and the smallest radius of the listed planets, 1.94 Earth radii. Its orbital period is 30.8 days.

HD 110067 f is Neptune-like with a mass of 5.04 Earth masses and a radius of 2.6 Earth radii. Its orbital period of 41.1 days is the second-longest among the listed planets. Its mean density is 1.58 g/cm³, 0.286 times Earth's.

HD 110067 g is Neptune-like, with a reported upper limit of 8.4 Earth masses and a radius of 2.61 Earth radii; this is the second-largest radius among the listed planets. Its orbital period of 54.8 days is the longest among the listed planets.