Are a new type of planets and dark alone?

U.S. astronomers discovered what they explain as a new class of planets: 10 dark bodies floating lonely far from any host star. The discovery was detected in the center of the Milky Way. The scientists, who published the findings in the journal Nature, believe these planets, which are the size of Jupiter, were expelled from their original planetary systems.

According to Professor David Bennett, professor of astrophysics and cosmology at the University of Notre Dame in Indiana,

who led the research, the discovery not only confirms that such isolated planets do exist in space, but also indicates that they are very common. And there may be many more of these heavenly bodies have not been identified, added.

The researchers relied on observations of the galactic center of the Milky Way that astronomers held Japanese and New Zealand between 2006 and 2007. "We conducted a similar survey a population census in which we analyze a portion of the galaxy and, based on these data, we estimate overall numbers in the galaxy," explains Professor Bennett.

Analysis of these data showed evidence of 10 free-floating planets in space, all approximately the mass of Jupiter. But believe it could be many smaller planets also are isolated and without a parent star. "Probably the isolated floating planets are as common as planets, like Earth, orbiting a star," scientists say.

Events gravitational

"Our results suggest that planetary systems often become unstable and planets are ejected from their homes after a close encounter with another planet" Prof. David Bennett For finding the scientists used a technique called microlensing Observations in Astrophysics (MOA) of the Observatory on Mt John University in New Zealand, which is used to regularly scan the stellar population of the center of the Milky Way in search of called "gravitational microlensing events."

These occur when light from distant bright objects and curves around a massive object, like a star, located between the transmitter and receiver object. With this technique, astronomers have also detected the presence of invisible massive objects like black holes.

As Professor Bennett explains, "Our survey did not include planets with masses less than Jupiter and Saturn, but theories suggest that mass planets smaller than the Earth have to be expelled from their systems more often." "And so they should be more common than these isolated bodies floating," he adds.

Astronomers do not know where they originated these dark bodies, but believe they were expelled from developing systems. "Our results suggest that planetary systems often become unstable and planets are ejected from their homes after a close encounter with another planet," said Professor Bennett.

Neither rule out the possibility that some of these isolated planets are moving in very distant orbits a star, but this, they say, is a rare phenomenon with planets of this mass. They plan to conduct further observations with the Hubble Space Telescope with which, they say, it will be possible to detect these host stars, if they exist.