Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Torn apart by its own tides, massive planet is on a 'death march'

25.02.2010
An international group of astrophysicists has determined that a massive planet outside our Solar System is being distorted and destroyed by its host star – a finding that helps explain the unexpectedly large size of the planet, WASP-12b.

It’s a discovery that not only explains what’s happening to WASP-12b; it also means scientists have a one-of-a-kind opportunity to observe how a planet enters this final stage of its life. “This is the first time that astronomers are witnessing the ongoing disruption and death march of a planet,” says UC Santa Cruz professor Douglas N.C. Lin,. Lin is a co-author of the new study and the founding director of the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University, which was deeply involved with the research.

The findings are being published in the February 25 issue of Nature.

The research was led by Shu-lin Li of the National Astronomical Observatories of China. A graduate of KIAA, Li and a research team analyzed observational data on the planet to show how the gravity of its parent star is both inflating its size and spurring its rapid dissolution.

WASP 12-b, discovered in 2008, is one of the most enigmatic of 400-plus planets that have been found outside our Solar System over the past 15 years. It orbits a star, in the constellation Auriga, roughly similar in mass to our Sun. Like most known extra-solar planets, it is large and gaseous, resembling Jupiter and Saturn in this respect. But unlike Jupiter, Saturn or most other extra-solar planets, it orbits its parent star at extremely close range – 75 times closer than the Earth is to the Sun, or just over 1 million miles. It is also larger than astrophysical models would predict. Its mass is estimated to be almost 50% larger than Jupiter’s and its 80% larger, giving it six times Jupiter’s volume. It is also unusually hot, with a daytime temperature of more than 2500°C.

Some mechanism must be responsible for expanding this planet to such an unexpected size, say the researchers. They have focused their analysis on tidal forces, which they say are strong enough to produce the effects observed on WASP 12b.

On Earth, tidal forces between the Earth and the Moon cause local sea levels rise and fall modestly ll twice a day. WASP-12b, however, is so close to its host star that the gravitational forces are enormous. The tremendous tidal forces acting on the planet completely change the shape of the planet into something similar to that of a rugby or American football.

These tides not only distort the shape of WASP 12-b. By continuously deforming the planet, they also create friction in the its interior. The friction produces heat, which causes the planet to expand. “This is the first time that there is direct evidence that internal heating (or ‘tidal heating’) is responsible for puffing up the planet to its current size,” says Lin.

Huge as it is, WASP 12-b faces an early demise, say the researchers. In fact, its size is part of its problem. It has ballooned to such a point that it cannot retain its mass against the pull of its parent star’s gravity. As the study’s lead author Li explains, ““WASP-12b is losing its mass to the host star at a tremendous rate of six billion metric tons each second. At this rate, the planet will be completely destroyed by its host star in about ten million years. This may sound like a long time, but for astronomers it's nothing. This planet will live less than 500 times less than the current age of the Earth.”

The material that is stripped off WASP-12b does not directly fall onto the parent star. Instead, it forms a disk around the star and slowly spirals inwards. A careful analysis of the orbital motion of WASP-12b suggests circumstantial evidence of the gravitational force of a second, lower-mass planet in the disk. This planet is most likely a massive version of the Earth -- a so-called “super-Earth.”

The disk of planetary material and the embedded super-Earth are detectable with currently available telescope facilities. Their properties can be used to further constrain the history and fate of the mysterious planet WASP-12b.

In addition to KIAA, support for the WASP 12-b research came from NASA, Jet Propulsion Laboratory and the National Science Foundation. Along with Li and Lin, co-authors include UC Santa Cruz professor Jonathan Fortney and Neil Miller, a graduate student at the university.

James Cohen | EurekAlert!
Further information:
http://www.kavlifoundation.org
http://www.kavlifoundation.org/kavli-news/KIAA-WASP-12b

More articles from Physics and Astronomy:

nachricht Breakthrough with a chain of gold atoms
17.02.2017 | Universität Konstanz

nachricht New functional principle to generate the „third harmonic“
16.02.2017 | Laser Zentrum Hannover e.V.

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>