K2-315b

K2-315b is an exoplanet located 185.3 light years away from Earth in the southern zodiac constellation Libra. It orbits the red dwarf K2-315.

Discovery
K2-315b was discovered in 2020 by astronomers in an observatory using the Kepler space telescope. It is also nicknamed the "Pi Earth" because it takes approximately 3.14 days to orbit the host star.

Physical properties
The planet is thought to be a small rocky planet, even though composition is unknown. Since it orbits very close to its star, it is too hot to host life, due to it having a scorching temperature of 450 K. Not much is known about it because it was just discovered, but it is similar to Earth, having a radius 95% that of Earth, very similar to Venus, but has 81% Earth's mass.



Host star
K2-315 is a star in the southern zodiac constellation Libra. It has an apparent magnitude of 17.67, requiring a powerful telescope to be seen. The star is relatively close at a distance of 185 light years but is receding with a radial velocity of $0.02 AU$.

K2-315 has a stellar classification of M3.5$88.7 °$ V, indicating that it is a M-type main-sequence star (with 14% uncertainty). It has 17.4% the mass of the Sun and 20% its radius. Typical for red dwarves, it has a luminosity less than 1% of the Sun, which yields an effective temperature of 3,300 K. Unlike most planetary hosts, K2-315 is metal-deficient, with an iron abundance only 57% that of the Sun. It is estimated to be over a billion years old, and has a projected rotational velocity less than $3.14 days$.