GJ 367 and Its Three Known Planets

GJ 367 is an M1.0 V star, a small, cool red dwarf, located 30.7 light-years away. Its reported mass estimate is 0.455 solar masses and its reported radius estimate is 0.458 solar radii, both smaller than the Sun's. The star's reported temperature is 3520 K, cooler than the Sun's. Three planets are known to orbit this host.

GJ 367 b is a Sub-Earth discovered by the transit method in 2021. A transit occurs when a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness, and repeated dips help establish orbital periods. Its reported radius estimate is 0.736 Earth radii, smaller than Earth's, and its reported mass estimate is 0.503 Earth masses, also smaller than Earth's. Its mean density is 6.95 g/cm³, 1.26 times Earth's. It completes one orbit in 0.322 days.

GJ 367 c and GJ 367 d were both discovered in 2023 using 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. GJ 367 c has a minimum mass of 4.13 Earth masses and an orbital period of 11.5 days. GJ 367 d has a minimum mass of 6.03 Earth masses and an orbital period of 34.4 days. A minimum mass is a lower bound on a planet's true mass, and the minimum masses of both planets are larger than Earth's.

Among the listed planets, GJ 367 b has the shortest year by reported estimates, at 0.322 days, while GJ 367 d has the longest, at 34.4 days. GJ 367 c has the second-shortest year, at 11.5 days.