Haumea (136108 Haumea) is a presumed dwarf planet discovered in 2004.
By current determinations, it is ellipsoid in
shape, with a mean 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.