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New Dwarfs

June 11, 2011

There's a sort of population explosion in the outer solar system -- three new possible dwarf planets beyond the orbit of Neptune, the largest major planet.

The dwarfs were discovered by a team led by Scott Sheppard and Andrzej Udalski. The astronomers were using a University of Warsaw telescope in Chile equipped with a new camera to search a large swath of the southern sky. Their quest was Kuiper Belt Objects -- iceballs in a wide band beyond Neptune.

The search revealed 14 new objects. Three of them appear to be large enough to be classified as dwarf planets -- objects that are big enough to pull themselves into a roughly spherical shape, but not big enough to clear out their orbits around the Sun. The most famous dwarf planet is Pluto, but the list already includes four others.

The possible new dwarfs are likely at least 250 miles in diameter -- about a quarter the size of Pluto. Their average distances from the Sun range from a bit more than Pluto's distance to almost five times its distance.

An orbiting infrared telescope has already looked at one of the three to try to refine the estimates of its size. Later, astronomers may be able to watch the objects pass in front of distant stars to further refine the sizes.

For now, the objects are designated 2010 EK139, KZ39, and FX86. Once their sizes are confirmed, though, they'll get proper names -- officially joining the growing ranks of dwarf planets.


Script by Damond Benningfield, Copyright 2011


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