An Etymological Dictionary of Astronomy and Astrophysics

A → dwarf planet located beyond → Neptune’s orbit (→ trans-Neptunian object). Haumea is roughly the same size as → Pluto.

It spins on its axis once every four hours, making it the fastest spinning known large object in the → solar system. It has two known moons, called Hi’aka and Namaka.

Observations from multiple Earth-based observatories of Haumea passing in front of a distant star indicate the presence of a ring with a width of 70 km and radius of about 2,287 km. The ring is coplanar with both Haumea’s equator and the orbit of its satellite Hi’aka.

The → occultation by the main body indicates an oblong shape for Haumea
with axes of about 2,322 × 1,701 × 1,138 km. In other words, along one direction, Haumea is significantly longer than → Pluto, while in another direction it has an extent very similar to Pluto, while in the third direction is much smaller. Haumea’s orbit sometimes brings it closer to the Sun than Pluto, but usually Haumea is further (Ortiz et al., 2017, Nature 550, 219, doi:10.1038/nature24051).

See also: Named for the Hawaiian goddess of childbirth and fertility (temporary designation 2003 EL61). Its moons are named for daughters of Haumea.