K2-16: A K-Type Dwarf with Three Known Planets

K2-16 is a K3 V star located 1090 light-years away. Its spectral type identifies it as a main-sequence dwarf. Its reported properties place it below the Sun in several respects: it has a mass of 0.68 solar masses, a radius of 0.66 solar radii, and a temperature of 4740 K. Its mass and radius are both smaller than the Sun's, and its temperature is cooler. Three planets orbit this host.

EPIC 201754305 d is an Earth-like world with a radius of 1.03 Earth radii and an orbital period of 2.72 days. Among the listed planets, it has the shortest year and the smallest radius. It was discovered by the transit method in 2019, which detects the slight dimming of a star as a planet crosses in front of it.

K2-16 b is a Super-Earth with a radius of 2.02 Earth radii and an orbital period of 7.62 days. Among the listed planets, it has the second-shortest year and the second-smallest radius. Its radius is larger than Earth's. It was discovered by transit in 2015.

K2-16 c is a Neptune-like planet with a radius of 2.54 Earth radii and an orbital period of 19.1 days. Among the listed planets, it has the longest year and the largest radius. Its radius is also larger than Earth's. Like the other two planets, it was discovered by transit, in 2015.

The three planets differ substantially in size, ranging from the Earth-like radius of EPIC 201754305 d to the Neptune-like radius of K2-16 c, and their orbital periods span from 2.72 days to 19.1 days.