K2-3 is a cool M-dwarf (about 0.55 solar masses, 3,844 K, 0.55 solar radii), 44.1 light-years from Earth. K2-3 b is a 5.1-Earth-mass planet, with an orbital period of 10.1 days, at 0.075 AU from its star, and an equilibrium temperature near 501 K, on an eccentric orbit (e ≈ 0.11), discovered in 2015 via transit. K2-3 c is a 2.7-Earth-mass planet, with an orbital period of 24.6 days, at 0.136 AU from its star, and an equilibrium temperature near 372 K, discovered in 2015 via transit.