It's now, officially, a "plutonian object"
2006-Aug-24, Thursday 14:47BBC reports that the resolution is passed.
ETA: They rejected resolution 5B, which means that a dwarf planet is not a type of planet, but a wholly different thing. So they've both redefined the solar system and the rules of grammar. Go IAU!
RESOLUTION 5AYou'd have thought that, during their biggest conference news in years, they'd manage to not schedule essential maintenence on their main website? Mirrors are fine, but the mirroe is way down the Google results for them.
The IAU therefore resolves that planets and other bodies in our Solar System be defined into three distinct categories in the following way:
(1) A planet1 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, and (c) has cleared the neighbourhood around its orbit.
(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) shape2, (c) has not cleared the neighbourhood around its orbit, and
(d) is not a satellite.
(3) All other objects3 orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".
( full text )
ETA: They rejected resolution 5B, which means that a dwarf planet is not a type of planet, but a wholly different thing. So they've both redefined the solar system and the rules of grammar. Go IAU!