Haumea

Haumea (136108 Haumea) is a presumed dwarf planet discovered in 2004. Its radius is roughly 780 km, its mass about a third that of Pluto, and its rotation period is 3.9 hours: the shortest of any 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 and with an orbital inclination of 24° from the ecliptic. Current thought is that it does not share an orbital resonance with Neptune. Two moons and a ring have been detected.