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: Unique pair of supermassive black holes in an ordinary galaxy discovered

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

A star's early chemistry shapes life-friendly atmospheres

18 hours ago

Born in a disc of gas and rubble, planets eventually come together as larger and larger pieces of dust and rock stick together. They may be hundreds of light-years away from us, but astronomers can nevertheless ...

Image: X-raying the cosmos

Apr 22, 2014

When we gaze up at the night sky, we are only seeing part of the story. Unfortunately, some of the most powerful and energetic events in the Universe are invisible to our eyes – and to even the best optical ...

Mysteries of nearby planetary system's dynamics solved

Apr 22, 2014

Mysteries of one of the most fascinating nearby planetary systems now have been solved, report authors of a scientific paper to be published by the journal Monthly Notices of the Royal Astronomical Society in its ...

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.

More news stories

How many moons does Venus have?

There are dozens upon dozens of moons in the Solar System, ranging from airless worlds like Earth's Moon to those with an atmosphere (most notably, Saturn's Titan). Jupiter and Saturn have many moons each, ...

First-of-its-kind NASA space-weather project

A NASA scientist is launching a one-to-two-year pilot project this summer that takes advantage of U.S. high-voltage power transmission lines to measure a phenomenon that has caused widespread power outages ...