For the first time a new image of the disk and dust around a sun-like star shows spiral-arm-like-structures. These features may provide clues to the presence of embedded but as a yet unseen planets.
This image was revealed by Carol Grady at the Signposts of Planets meeting who is an astronomer with Eureka Scientific, Inc., who is based at NASA's Goddard Space Flight Center in Greenbelt, Md. She said,"Detailed computer simulations have shown us the gravitational pull of a planet inside a circumstellar disk can perturb gas and dust, creating spiral arms. Now, for the first time, we're observing these dynamical features." Grady's research is part of the Strategic Exploration of Exoplanets and Disks with Subaru (SEEDS), a five-year-long near infrared study of young stars and their surrounding dust disks using Subaru Telescope atop Mauna Kea in Hawaii.
John Wisniewski, a collaborator at the University of Washington in Seattle remarks,"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. Many of these structures could be caused by planets within the disks."
The newly imaged disk that spans some 14 billion miles (more than twice the size of Pluto's orbit in our own solar system) that surrounds SAO 206462, an 8.7 magnitude star located about 456 light years away in the constellation Lupus is estimated to be only about 9 million years old.
The Subaru near-infrared image reveals a pair of spiral features arcing along the outer disk. Theoretical models show that a 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 researchers team cautions that processes unrelated to planets may give rise to these structures.
SEEDS principle investigator Motohide Tamura at National Astronomical Observatory of Japan, which operates the telescope states that,"Together with improvements to Subaru's adaptive optics system, which counteracts the blurring effects of Earth's atmosphere, the telescope is operating near its theoritical performance limits. We are just beginning to see what it will do."
"The Signposts of Planets meeting is all about understanding these kinds of patterns,"said NASA's Goddard's Marc Kuchner, who organized the conference. "It's a new kind of planet-hunting technique that is just now coming to fruition, and this new image from SEEDS is that perfect example of how it can work."
[via: nasa.gov.in]
John Wisniewski, a collaborator at the University of Washington in Seattle remarks,"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. Many of these structures could be caused by planets within the disks."
The newly imaged disk that spans some 14 billion miles (more than twice the size of Pluto's orbit in our own solar system) that surrounds SAO 206462, an 8.7 magnitude star located about 456 light years away in the constellation Lupus is estimated to be only about 9 million years old.
The Subaru near-infrared image reveals a pair of spiral features arcing along the outer disk. Theoretical models show that a 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 researchers team cautions that processes unrelated to planets may give rise to these structures.
SEEDS principle investigator Motohide Tamura at National Astronomical Observatory of Japan, which operates the telescope states that,"Together with improvements to Subaru's adaptive optics system, which counteracts the blurring effects of Earth's atmosphere, the telescope is operating near its theoritical performance limits. We are just beginning to see what it will do."
[via: nasa.gov.in]
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