Mysterious ‘zombie planet’ has rogue orbit around star

January 09, 2013

Mysterious ‘zombie planet’ has rogue orbit around star

A zombie planet rises from the dead.

Astronomers remain puzzled by a recent finding of a “zombie planet” that seems to have a rogue orbit.

“We are shocked. This is not what we expected,” said study leader Paul Kalas, an astronomer with the University of California at Berkeley and the SETI Institute in Mountain View, California, in a statement Tuesday.

The planet — known as Fomalhaut b — is an alien planet three times larger than Jupiter and it is the first planet ever imaged in visible light, according to astronomers. Newly obtained data shows the planet follows an unusual elliptical orbit that carries it on a potentially destructive path. According to astronomers, the planet remains stuck in an orbit that takes in through the star system’s debris disk while, meanwhile, it continues to stray farther away from its home star.

Astronomers say the debris disk around nearby star Fomalhaut and the mysterious planet may be clues to a titanic planetary disruption in the system. The star system could collapse at some point, and with it being a ‘mere’ 25 light years from us, it could provide astronomers with a stunning cosmic show. It remains unclear when the star system will face its decisive moment, but astronomers are likely eager to witness the change. According to Kalas, the star system is similar to our own when it began to evolve four billion years ago.

Kalas hypothesizes that Fomalhaut b’s extreme orbit may serve as a major clue for why the planet is unusually bright in visible light, but very dim in infrared light. It is possible the planet’s optical brightness originates from a ring or shroud of dust around the planet, which reflects starlight. The dust would be rapidly produced by satellites orbiting the planet, which would suffer extreme erosion by impacts and gravitational stirring when Fomalhaut b enters into the planetary system after a millennium of deep freeze beyond the main belt. Kalas compared it to Saturn, saying some of the outer planets in our own solar system may have gone through a similar state of evolution.

“Hot Jupiters get tossed through scattering events, where one planet goes in and one gets thrown out,” says Mark Clampin of NASA’s Goddard Space Flight Center. “This could be the planet that gets thrown out.”

Astronomers dubbed the world a “zombie planet” in October 2012 due to the fact it appears to have risen from the academic grave. The large debris disk is similar to the Kuiper Belt, which encircles the solar system and contains a range of icy bodies from dust grains to objects the size of dwarf planets, such as Pluto, making it difficult to detect planets.

Following the planet’s discovery in 2008, subsequent studies had revealed the planet was little  more than a huge dust cloud. Researchers, in 2012, employed the resources of NASA’s Hubble, seeking confirmation that the ring is offset from the center of the star. Hubble eventually confirmed that the sharp inner edge of the ring is consistent with the presence of a planet that gravitationally “shepherds” ring particles. The findings was verified by independent researchers who subsequently reached similar conclusions.

 


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