Star dust shows planet potential

Advertiser Staff

Astronomers using the Submillimeter Array telescope atop Mauna Kea have confirmed that many young stars in the Orion Nebula are surrounded by enough orbiting material to form new planetary systems.

"The SMA is the only telescope that can measure the dust around these stars, and thereby assess their true potential for forming planets. This is critical to our understanding of how solar systems form in hostile regions of space," said Jonathan Williams of the University of Hawai'i's Institute for Astronomy.

The objects were first seen by the Hubble Space Telescope in 1992 as "misshapen silhouettes against the nebular background," according to an announcement yesterday from the Institute for Astronomy. They were called "proplyds" — for "protoplanetary disks" — on the assumption that they consisted of newly formed stars surrounded by a disk of matter from which new planets are forming. They are among the youngest stars in the galaxy at about 1 million years old.

"The Hubble telescope showed us the size of the disks, but not how much material they contained," said UH graduate student Sean Andrews, who worked with Williams on the research, along with David Wilner of the Harvard-Smithsonian Center for Astrophysics.

With winds inside the Orion Nebula reaching 2 million mph and temperatures exceeding 18,000 degrees Fahrenheit, there were questions about whether the proplyds would eventually disintegrate under the brutal conditions.

But "it now appears that these protoplanetary disks are quite tenacious, bringing new grounds for optimism in the search for planetary systems," the announcement said.

Since some of the disks appear to be comparable in size and mass to our solar system, UH astronomers said this strengthens the connection between the Orion proplyds and the origins of our system. The research also suggests that the formation of solar systems is common and a continuing event in the galaxy.

The SMA is the world's first imaging interferometric telescope that receives radiation signals at the submillimeter wavelengths to see into dense interstellar clouds. It consists of an array of eight movable reflector antennas, each nearly 20 feet in diameter.