Evaporating exoplanet stirs up dust

Aug 28, 2012
© C.U Keller, Leiden University (2012)

Dutch astronomers have found clear evidence that a faraway exoplanet is falling apart. New analysis of data from NASA's Kepler satellite shows that this exoplanet, which orbits its host star every 16 hours, has a massive dust tail originating from its surface, similar to a comet's tail. The study will be published in the journal Astronomy & Astrophysics.

The satellite is looking for planets around stars other than the Sun, known as exoplanets, since the spring of 2009. When an exoplanet moves in front of its , the starlight is dimmed by a small amount. By looking at over 145,000 stars simultaneously, Kepler can find these rare exoplanet transits and thereby detect thousands of exoplanets. Earlier this year scientists in the US found a mysterious object among the stars observed by Kepler: instead of constant, periodic dimming due to a transiting exoplanet, KIC 12557548 shows periodic dimming that strongly vary in strength. This led to the speculation that the variable signal may be due to an exoplanet that is slowly falling apart. Now, a new, much more detailed analysis of Kepler data clearly shows that starlight is scattered by a large dust cloud that trails the planet. So far this is the only known exoplanet of its kind.

"The exoplanet is very close to its central star", explains Matteo Brogi (Leiden University), lead author of the study. "Because it is so close, the surface of this is very hot, about 2000 degrees Kelvin. This leads to very strong internal motions in the planet, which in turn leads to massive volcanism and erupting ash clouds. Some of this dust escapes into space where the intense stellar radiation quickly evaporates it. The variable amount of dust leads to the observed variability in the star's dimming."  Christoph Keller (Leiden University), co-author of the publication adds: "By observing the dust clouds in different colors, something Kepler cannot do, we will be able to determine the amount and the composition of the dust and estimate its lifetime. As the evaporation peels the planet like an onion, we can now see what used to be the inside of a planet".

Explore further: Image: Chandra's view of the Tycho Supernova remnant

More information: Evidence for the disintegration of KIC 12557548 b; M. Brogi, C. U. Keller, M. de Juan Ovelar, M. A. Kenworthy, R. J. de Kok, M. Min, I. A. G. Snellen. arxiv.org/abs/1208.2988

add to favorites email to friend print save as pdf

Related Stories

An exoplanet orbiting a double star

Oct 03, 2011

(PhysOrg.com) -- The Kepler satellite, which has now reported the detection of 1781 candidate exoplanets (a planet around a star other than the sun), has also discovered that at least one of them orbits a ...

Newfound exoplanet may turn to dust

May 18, 2012

Researchers at MIT, NASA and elsewhere have detected a possible planet, some 1,500 light years away, that appears to be evaporating under the blistering heat of its parent star. The scientists infer that a ...

Alien world is blacker than coal

Aug 11, 2011

(PhysOrg.com) -- Astronomers have discovered the darkest known exoplanet - a distant, Jupiter-sized gas giant known as TrES-2b. Their measurements show that TrES-2b reflects less than one percent of the sunlight ...

Recommended for you

Comet Jacques makes a 'questionable' appearance

7 hours ago

What an awesome photo! Italian amateur astronomer Rolando Ligustri nailed it earlier today using a remote telescope in New Mexico and wide-field 4-inch (106 mm) refractor. Currently the brightest comet in ...

Image: Our flocculent neighbour, the spiral galaxy M33

8 hours ago

The spiral galaxy M33, also known as the Triangulum Galaxy, is one of our closest cosmic neighbours, just three million light-years away. Home to some forty billion stars, it is the third largest in the ...

Image: Chandra's view of the Tycho Supernova remnant

Jul 25, 2014

More than four centuries after Danish astronomer Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is now a bright source of X-rays. The supersonic expansion of ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Argiod
1 / 5 (2) Aug 28, 2012
I'll have my exo-planet well done, please.