Spiral arms hint at the presence of planets

Oct 19, 2011
Two spiral arms emerge from the gas-rich disk around SAO 206462, a young star in the constellation Lupus. This image, acquired by the Subaru Telescope and its HiCIAO instrument, is the first to show spiral arms in a circumstellar disk. The disk itself is some 14 billion miles across, or about twice the size of Pluto's orbit in our own solar system. Credit: NAOJ/Subaru

A new image of the disk of gas and dust around a sun-like star has spiral-arm-like structures. These features may provide clues to the presence of embedded but as-yet-unseen planets.

"Detailed have shown us that the gravitational pull of a planet inside a circumstellar disk can perturb gas and dust, creating . Now, for the first time, we're seeing these features," said Carol Grady, a National Science Foundation (NSF)-supported astronomer with Eureka Scientific, Inc.

The newly imaged disk surrounds SAO 206462, a star located about 456 light-years away in the constellation Lupus. Astronomers estimate that the system is only about 9 million years old. The gas-rich disk spans some 14 billion miles, which is more than twice the size of Pluto's orbit in our own solar system.

"The surprise," said Grady, "was that we caught a glimpse of this stage of . This is a relatively short-lived phase."

A near-infrared image from the National Astronomical Observatory of Japan shows a pair of spiral features arcing along the outer disk. show that a single embedded planet may produce a spiral arm on each side of a disk. The structures around SAO 206462 do not form a matched pair, suggesting the presence of two unseen worlds, one for each arm. However, the research team cautions that processes unrelated to planets may also give rise to these structures.

"What we're finding is that once these systems reach ages of a few million years, their disks begin to show a wealth of structure--rings, divots, gaps and now spiral features," said John Wisniewski, a collaborator at the University of Washington in Seattle. "Many of these structures could be caused by planets within the disks."

Grady's research is part of the Strategic Exploration of and Disks with Subaru (SEEDS), a five-year-long near-infrared study of young stars and their surrounding dust disks using the atop Mauna Kea in Hawaii. The international consortium of researchers now includes more than 100 scientists at 25 institutions.

"These arm-like structures have been predicted by models, but have never before been seen," said Maria Womack, program director for the division of Astronomical Sciences at NSF. "It is the first observation of spiral arms in a circumstellar disk, and an important test for models of planetary formation."

Explore further: How we found the source of the mystery signals at the Dish

Related Stories

First Direct Imaging of a Young Binary System

Dec 15, 2009

(PhysOrg.com) -- A team of astronomers from The Graduate University for Advanced Studies, the National Astronomical Observatory of Japan, and other universities have captured the first direct image of a young ...

A new, distant arm of the Milky Way galaxy

Jun 13, 2011

(PhysOrg.com) -- Our Milky Way galaxy, like other spiral galaxies, has a disk with sweeping arms of stars, gas, and dust that curve around the galaxy like the arms of a huge pinwheel.

Back to the roots of the solar system

Feb 17, 2011

(PhysOrg.com) -- Planets form in disks of dust and gas that surround young stars. A look at the birth places means a journey into the past of the earth and its siblings. Now, astronomers have been able to ...

Planetary systems can form around binary stars

Jan 10, 2006

New theoretical work shows that gas-giant planet formation can occur around binary stars in much the same way that it occurs around single stars like the Sun. The work is presented today by Dr. Alan Boss of ...

Hubble Reveals Two Dust Disks Around Nearby Star

Jun 27, 2006

NASA's Hubble Space Telescope has revealed two dust disks circling the nearby star Beta Pictoris. The images confirm a decade of scientific speculation that a warp in the young star's dust disk may actually ...

Cosmic births revealed by disks of dust

Nov 15, 2010

By carving 'gaps' in the disks of dust that create and enshroud them, newborn planets are giving astronomers clues to locating possible new worlds.

Recommended for you

What are extrasolar planets?

15 hours ago

For countless generations, human beings have looked out at the night sky and wondered if they were alone in the universe. With the discovery of other planets in our solar system, the true extent of the Milky ...

A curious family of giant exoplanets

16 hours ago

There are 565 exoplanets currently known that are as massive as Jupiter or bigger, about one third of the total known, confirmed exoplanet population. About one quarter of the massive population orbits very ...

Astrobiology students explore alien environment on Earth

16 hours ago

Sonny Harman never thought he'd be able to travel far enough to do field work. That's because the Penn State doctoral student studies atmospheres on other planets. But to his surprise, Harman recently stepped ...

NASA image: Hubble revisits tangled NGC 6240

17 hours ago

Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Digi
not rated yet Oct 19, 2011
It is always a special moment when structures predicted by models are seen observationally. And this one was worth waiting for.
Callippo
not rated yet Oct 19, 2011
IMO the geometry of epicycles in spiral protoplanetary disks could explain the Titus-Body law and/or even Keplers model of solar system based on Platonic solids.

http://www.uff.br...-en.html

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.