Distant star may be a mimic solar system

By Jan TenBruggencate
Advertiser Science Writer

Astronomers at the Keck II Observatory atop Mauna Kea have discovered disks around a distant sun that suggest tantalizing similarities to our own solar system.

The star is Beta Pictoris, which is visible to the naked eye in winter, about 20 degrees above the southern horizon in the constellation Pictor, the painter's easel.

Previous work discovered two outer disks around Beta Pictoris, but a team led by University of Pennsylvania astronomer David Koerner spotted an inner disk in the same zone as the planets of our system.

"This is the first time we have imaged a feature so close to a star that might be evidence for a planet," said Zahed Wahhaj, a graduate student working with Koerner.

The Beta Pictoris disks lie on different planes, one of them canted 14 degrees off the main disk and the other 4 degrees off the main disk — oddly reminiscent of our solar system.

"Pluto's orbit is inclined by 17 degrees compared to Earth's, and Mercury's differs by 7 degrees ... ," Koerner said. "The new Keck images may be interpreted as circumstantial evidence for a similarly organized planetary system."

Beta Pictoris is a relatively young star, just 20 million years old, and about 63 light years from Earth.

Another team of researchers imaged the same inner disk using the Keck I observatory. They found that the inner disk is composed of small silicate particles that may be colliding with each other in response to the gravity of a nearby planet, said Alycia Weinberger, now at the Carnegie Institution of Washington.

Details and images are available at www.hep.upenn.edu/~davidk/bpic.html.

Correction: The star Beta Pictoris is about 63 light years from Earth. A previous version of this story had an incorrect distance.