K2-166 is a Sun-like G-type star (about 1.16 solar masses, 5,960 K, 1.61 solar radii), 477 light-years from Earth. K2-166 b is a planet with 2.2 Earth radii, with an orbital period of 8.5 days, at 0.086 AU from its star, and an equilibrium temperature near 1,140 K, discovered in 2018 via transit. EPIC 201615463 c is a planet with 1.2 Earth radii, with an orbital period of 3.8 days, discovered in 2019 via transit. The planet was found when it crossed the face of its star, producing periodic dips in brightness that reveal its size and orbital period to space-based photometry.