K2-285: A K-Type Dwarf and Its Four Transiting Planets

K2-285 is a K2 V star located 505 light-years away. This classifies it as a main-sequence dwarf, and its reported mass estimate is 0.83 solar masses, its radius estimate 0.787 solar radii, and its temperature 4980 K. The star is therefore less massive, smaller, and cooler than the Sun. Four planets are known to orbit it.

All four were discovered by transit in 2018 and are classed by radius. K2-285 b and K2-285 c are Neptune-like, while K2-285 d and K2-285 e are Super-Earths. K2-285 b has a mass of 9.68 Earth masses, a radius of 2.59 Earth radii, and an orbital period of 3.47 days; its mean density is 3.07 g/cm³, 0.557 times Earth's. Its year is the shortest among the listed planets. K2-285 c has a mass of 15.7 Earth masses, a radius of 3.53 Earth radii, and an orbital period of 7.14 days, the second-shortest year; its mean density is 1.96 g/cm³, 0.356 times Earth's. Its radius is the largest of the four, while K2-285 b's is the second-largest.

K2-285 d has a reported upper limit of 6.5 Earth masses, a radius of 2.48 Earth radii, and an orbital period of 10.5 days, the second-longest year. K2-285 e has a reported upper limit of 10.7 Earth masses, a radius of 1.95 Earth radii, the smallest among the four, and an orbital period of 14.8 days, the longest year.