Dec 3, 2015

Exoplanet Hurled Into Exile After Gravitational Rumble

A massive planet orbiting about 650 times farther from its parent star than Earth circles the sun appears to have been booted into the outskirts, a graphic illustration of what may have happened to our solar system’s early family.

The planet, which is about 11 times bigger than Jupiter, has been a puzzle since its discovery in 2014. It is located so far from its parent star — about 16 times farther away than Pluto orbits the sun — that astronomers first thought it must have formed like a star, condensing out of its own cloud of gas and dust.

But a new study indicates a much more violent past. The planet, known as HD 106906b, seems to have been shot out from a cozier perch in the star’s planet-forming region to its distant backyard by an as-yet undetected missing massive planet or by a passing star.

Evidence for the extreme migration comes from a newly discovered belt of comets orbiting the star, much like the Kuiper Belt circles the sun.

But the star’s comet belt is severely lopsided, raising suspicions that the same gravitational forces that disturbed the comets led to HD 106906b’s exile.

Astronomers are now on the hunt for dusty material from the comets that may have been swept into orbit around the planet.

“We think that the planet itself could have captured material from the comet belt, and that the planet is surrounded by a large dust ring or dust shroud,” astronomer Paul Kalas, with the University of California Berkeley, said in a statement.

“We conducted three tests and found tentative evidence for a dust cloud, but the jury is still out,” Kalas said.

Meanwhile, the story of HD 106906b  has scientists wondering if our solar system took a similar beating in its youth, possibly losing a planet or two in the process.

Read more at Discovery News

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