Haumea
[1] named after the Hawaiian goddess of childbirth and fertility and
officially designated a "dwarf planet" [2] by the International
Astronomical Union on September 17, 2008, is at present the newest
member of the solar family.
It was co-discovered by
a Caltech team headed by M. E. Brown, on December 28, 2004,
(based on
images taken on May 6, 2004,) and by J. L. Ortiz’s team at
Sierra
Nevada Observatory in Spain on July 29, 2005, (based on images
taken March 7, 2003,) [3] and is unique amongst
dwarf planets (although the tiny world's gravity is sufficient to meet
the "nearly
round"
requirement, a rapid rotation possibly due to the same impact
which produced its two moons has dramatically elongated it).
An
orbit of 34.72 AU at Perihelion and 51.54 AU at Aphelion places
this trans-Neptunian object (plutoid) squarely in the Kuiper belt, [4]
its location part way between Pluto and Makemake.
Spectroscopic
analysis of Haumea seems to indicate a surface of almost pure ice
surrounding a rocky core.
Its
size is estimated to be roughly that of Makemake (probably slightly
smaller), with a mass a third that of Pluto. Its
surface temperature is approximately -240 °C.
Its
atmosphere, if any, an unknown.
[1]
Originaly nicknamed Santa by the Caltech team because of the date of
discovery (December 28). [2] A "dwarf
planet" is a celestial body that (a) is in orbit
around the Sun, (b) has sufficient mass for its self-gravity to
overcome rigid body forces so that it assumes a hydrostatic equilibrium
(nearly round shape), (c) has not cleared the neighborhood around its
orbit and (d) is not a satellite.
[3]
In truth both the date of discovery and the names of the discoverers
are still a matter of contention. [4]
The Kuiper belt is a region of the outer Solar
System populated by
billions of rock-ice objects. It reaches from the orbit of Neptune
(30 AU) outward to approximately 55 AU.
