Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hidden Planet Pushes Star's Ring a Billion Miles Off-Center

14.06.2007
A young star's strange elliptical ring of dust likely heralds the presence of an undiscovered Neptune-sized planet, says a University of Rochester astronomer in the latest Monthly Notices of the Royal Astronomical Society.

Stars in the early stages of life are surrounded by dust clouds that thin out and dissipate as the star reaches maturity, becoming rings in their final stages. One star, however, has a dust ring that has long puzzled astronomers because it is not centered around the star as usual. Instead, the ring is elliptical, with the parent star off to one side.

"We wanted to know why this ring was off-center," says Alice C. Quillen, Associate Professor of Astronomy and author of the study. "People guessed there might be a planet in there, but nobody knew where it might be, or how big it might be. Now we've got a very good idea."

Roughly 250 planets have been discovered so far around stars other than our Sun. Most have been revealed by the way the planets influence their parent stars, but Quillen has been working for years on understanding the delicate interaction between stellar dust disks and the planets that shape them. She is now one of the world's experts in predicting planet size and position from the features of a star's dust ring.

Quillen used new images from the Hubble Space Telescope that caught the star, Fomalhaut, and its surrounding ring almost edge-on and in more detail than ever before. Fomalhaut, 25 light-years away, is the brightest star in the autumn sky. Using a device called a coronagraph that blocks out a star's light so dimmer objects near it can be seen, the Hubble revealed that Fomalhaut was indeed off-center within its ring. The images were also clear enough to show that the ring itself had a surprisingly sharp edge.

That sharp edge was the clue Quillen was looking for. Since ascertaining one of the first extra-solar planets using dust-ring analysis in 2002, Quillen has greatly strengthened her planet-ring interaction models. Treating the ring like a hydrodynamic structure, for instance, is necessary for younger stars whose dust is relatively fine and acts more like a fluid—while the physics of dust collision become dominant in older ring systems where the dust has begun clumping into larger bodies.

The sharp inside edge of Fomalhaut, Quillen calculated, demanded that a relatively small, Neptune-size planet was tucked right up against the inner side of the ring, using its gravity to toss dust in the area out of orbit.

According to Quillen's calculations, the ring is elliptical because the Neptunian planet's own orbit around Fomalhaut is elliptical—a curiosity in such a young system. When stars form from a giant cloud of gas and dust, the angular momentum of the cloud carries over to all the objects that form from the cloud, including new planets. Those new planets should, initially at least, orbit in nice, circular paths—not elliptical ones. Fomalhaut's ring is offset by 1.4 billion miles, more than 15 times the distance from the Earth to the Sun, suggesting the hidden planet's orbit is also tremendously skewed.

"Something had to skew that planet, and that's what we're working on now," says Quillen. "There may have been fantastic planetary collisions early on that changed their orbits. We're working on figuring out how many more planets of what size you'd need to account for that elliptical orbit, and to account for why there is no other dust inside that ring."

Quillen's model will remain just a theory until a new generation of telescopes can actually see the Formalhaut planets in question. These telescopes will be equipped with sophisticated coronagraphs that can block out Formalhaut's light enough to let the planets themselves shine through.

This research was funded by the National Institutes of Science and NASA.

Jonathan Sherwood | EurekAlert!
Further information:
http://www.rochester.edu

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>