Friday, September 19, 2008

Number of Dwarf Planets Climbs to Five

Can you name all five dwarf planets? This week the International Astronomical Union announced the naming of the fifth one. Haumea (pronounced how-MAY-uh).

Although its discovery has been disputed, three of the five named dwarf planets (as sizable majority) have been found here at Palomar using the 48-inch Samuel Oschin Telescope. The graphic above shows the largest worlds that are known to lie beyond Neptune. Six of the eight worlds have been found using the Samuel Oschin Telescope.

The five named dwarf planets are: Ceres, Pluto, Eris, Makemake & Haumea.

2 comments:

Laurel Kornfeld said...

These five dwarf planets are planets, as they are in hydrostatic equilibrium, which means they have geophysical properties similar to planets. The IAU's ridiculous definition stating that dwarf planets are not planets at all must be revised. It's fine to use the term dwarf planet to refer to small planets that do not dominate their orbits, but it makes no sense to claim these are not planets at all. They are. Our solar system now has 13 planets and counting.

Palomar Observatory said...

Hi Laurel,

The debate rages on. Last month "The Great Planet Debate" was held on this very issue. There's a summary of what happened here:

http://www.psi.edu/press/archive/20080919planetdebate/