In the solar system shown a new planet

Exposed a new category of planets appear to suggest alone in space. This is called roaming worlds, which, far from any star, wandering through interstellar space after being ejected from planetary systems in which they formed. Now, new research from the Harvard-Smithsonian Center for Astrophysics suggests that these worlds’ nomads can find a new home with a different sun. He even claims that billions of stars in our galaxy may have caught wandering planets. This finding, which will be published in the journal Astrophysical Journal, could explain the existence of planets orbiting some surprisingly far from their stars, and even the existence of a double planet.

In reaching this conclusion, the researchers simulated young star clusters containing free-floating planets. They found that if the number of wandering planets equals the number of stars, from 3 to 6% of the stars end up attracting one of these worlds to your system.

They studied young star clusters, because the capture is more likely when the stars and planets that float freely crowd into a small space.

The wandering planets are a natural consequence of star formation. The newborn star systems often contain multiple planets. If two planets interact, one can be expelled and become an interstellar traveler. If later with a different star are moving in the same direction at the same speed, than can be "hooked" on the ride.

A planet tends to be captured hundreds or thousands of times far from its star than Earth is from the Sun is also likely to have an orbit inclined with respect to native planets, and can even turn around its star back.

A world away from Pluto

Astronomers have not found clear cases of captured planets, which can be easily confused. Finding a planet in a distant orbit around a low-mass star would be a good sign, because the disk of the star would not have had enough material to form the planet so far.

The best evidence found so far comes from the European Southern Observatory, which announced in 2006 the discovery of two planets (with a weight of 14 and 7 times Jupiter) orbiting each other, without a star. But our solar system could house a strange world far beyond Pluto? Astronomers have searched and have not found anything yet. "There is no evidence that the Sun has captured a planet," says the researcher Hagai Perets, one of the investigators. "We can rule out large planets, but there is a nonzero possibility that a small world might be lurking on the fringes of our solar system, "he qualifies.