Fomalhaut's Exoplanets Have Orbits That Defy Theory 43
astroengine writes "Astronomers believe they have found a second distant planet around Fomalhaut, a bright young neighbor star, and that the far-out world — like its sister planet — is shepherding and shaping the star's ring of dust. If confirmed, theorists have some work to do explaining how the planet, believed to be a few times bigger than Mars, ended up 155 times as far away from its parent star as Earth is to the sun. 'We're learning a lot about planets that are close to their stars, but that is not the full picture. We also want to know about systems where planets are very far out. By considering near-, far- and mid-range, we can get a complete picture of planet formation,' University of Florida astronomer Aaron Boley said."
There was another fascinating bit of news about Fomalhaut a few days ago: "ESA’s Herschel Space Observatory has studied the dusty belt around the nearby star Fomalhaut. The dust appears to be coming from collisions that destroy up to thousands of icy comets every day."
Re:Theory (Score:3, Informative)
So... what is the theory that its defying?
I think the theory is that rocky planets and dusty rings should be orbiting much closer to a star that's only twice as big as ours.
The suspected planet would be the second planet found orbiting Fomalhaut, a very bright star located about 25 light-years away in the constellation Piscis Austrinus. Fomalhaut is twice as big as our sun and encircled by a disk of dust 16 times wider than the span between the sun and Earth.
The inner edge of the ring is about 135 times as far as away from the star as Earth is to the sun.