Haumea

Haumea (136108 Haumea) is a presumed dwarf planet discovered in 2004. By current determinations, it is ellipsoid in shape, with an average radius of 780 km, a mass about a third that of Pluto, and a rotation period of 3.9 hours: the shortest of any known body of at least its size within the solar system. Its orbit is somewhat similar to Pluto's: eccentric, ranging roughly from 35 AU to 52 AU, with an orbital inclination of 28° from the ecliptic. Current thought is that it does not share an orbital resonance with Neptune, but possibly intermittently falls into a 7:12 resonance. Two moons (Hi'iaka and Namaka) and a ring have been detected.