TOI-4342: A Cool Dwarf with Two Super-Earths

TOI-4342 is an M0 V star, a small, cool red dwarf, located 201 light-years away. Its reported mass estimate is 0.587 solar masses, its radius is 0.598 solar radii, and its temperature is 3870 K. 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 is cooler than the Sun's. Two planets are known to orbit this host.

TOI-4342 b and TOI-4342 c are both Super-Earths, discovered by transit in 2023. A transit occurs when a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness. TOI-4342 b has a mass of 7.3 Earth masses, a radius of 2.33 Earth radii, and an orbital period of 5.54 days. TOI-4342 c has a mass of 4.8 Earth masses, a radius of 2.35 Earth radii, and an orbital period of 10.7 days. Both planets' reported radius estimates are larger than Earth's, and both planets' reported mass estimates are larger than Earth's.

Among the listed planets, TOI-4342 b has the shortest year by reported estimates at 5.54 days and the smallest radius by reported estimates at 2.33 Earth radii, while TOI-4342 c has the longest year by reported estimates at 10.7 days and the largest radius by reported estimates at 2.35 Earth radii. Among the listed planets, TOI-4342 b also has the largest reported mass at 7.3 Earth masses, and TOI-4342 c has the smallest reported mass at 4.8 Earth masses. TOI-4342 b's mean density is 3.18 g/cm³, 0.578 times Earth's, and TOI-4342 c's mean density is 2.04 g/cm³, 0.37 times Earth's.