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Planet Names

September 30, 2010

From Alderaan to Gallifrey to Vulcan, the fictional universe is populated with lots of planets with beautiful or interesting names. Who wouldn't like to visit Divine Wind -- or avoid Hell?

In the real universe, though, astronomers have a lot of work to do when it comes to naming planets. HD 13931 b sounds about as appealing as a tax audit.

Of course, we know very little about the worlds outside our own solar system, so there isn't a pressing need for better names -- not yet, anyway.

Astronomers designate an extrasolar planet with the name of its star followed by a letter, starting with "b." The letters are bestowed based on the order of discovery, not a planet's location within the system. In the system 55 Cancri, for example, the planets line up e, b, c, f, and d.

A few stars with known planets have names based on their constellations, but most simply have catalog numbers. That's where we get names like MOA-2008-BLG-310-L b -- a planet discovered by the Microlensing Observations in Astrophysics project, in 2008, in the central bulge of the Milky Way galaxy.

One bright star with a known planet and an easy name is in good view tonight. Fomalhaut is low in the southeast at nightfall, and due south around midnight. It's in a barren patch of sky, so it's easy to pick out. Hubble Space Telescope has taken a picture of its planet -- a tiny, faint dot known -- of course -- as Fomalhaut b.


Script by Damond Benningfield, Copyright 2010


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