HD 219666 is a Sun-like G-type star (about 1.02 solar masses, 5,540 K, 1.06 solar radii), 94.2 light-years from Earth. HD 219666 b is a 0.06-Jupiter-mass companion, with an orbital period of 6.0 days, and an equilibrium temperature near 1,076 K, discovered in 2018 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. With an equilibrium temperature around 1,076 K, the dayside atmosphere is hot enough to vaporise many common minerals.