This item caught my attention. Scientists have found a planet stably orbiting in a triple star system 149 light years from Earth:
The planet orbits the main star with a period of 3.35 days (distance from star: 4.5% Earth-Sun distance), while the other two stars orbit a common center of mass that orbits the main star every 25 years (elliptical orbit with average distance from main star: 12.3 times Earth-Sun distance). The planet is a Jupiter-like gas giant. (Helpful orbital diagram)
Here's an animation of what you'd see standing on a moon of the planet: [Quicktime]
What's the import?
But the paired companion stars to HD 188753's primary star, scientists now realize, would presumably have burned away the disk of gas and dust out of which a planet could have formed. According to the standard orbital migration model, the newfound planet should not exist.
Oh well. Back to the drawing board....
John Noble Wilford, "Discovery of a First: A World With 3 Suns" New York Times (July 15, 2005).
Mark Peplow, "The triple sunset that should not exist," Nature (online: 13 July 2005).
Maciej Konacki, "An extrasolar giant planet in a close triple-star system," Nature 436 (14 July 2005), 230-233.