Flying "Moth" Star, Stellar Quadruplets Discovered

collarian · 12-01-08, 19:43

Astronomers studying our corner of the galaxy have found a strange object that looks like a moth spreading its wings and a never before seen system of four tightly grouped stars.

The first of these phenomena, dubbed the Moth, is a disk of dust and gas illuminated by a young star in the constellation Puppis.

Such disks, believed to be made of the material from which planets form, are common around young stars.

But this one is oddly bent, as though flying into a headwind, and that's exactly what it's doing, said Glenn Schneider of the University of Arizona. Schneider was part of a team that took infrared images of the object with the Hubble Space Telescope.

"Dust grains normally orbit in a plane unless they're disturbed by something," he said yesterday at a meeting of the American Astronomical Society in Austin, Texas.

But in this case, he said, the star and its disk are plowing through an interstellar gas cloud.

"That produces a local wind that is blowing the dust backward, producing this meniscus-like [or crescent] shape," Schneider said.

"Intense Radiation"

The Moth was found as part of a systematic search for planet-forming disks that might shed light on how planetary systems, including our own, formed.

About 112 light-years from the sun, the Moth was detected because of the intense infrared light it emits.

"One of the things that drew us to this star system is how bright it is in the infrared," said Schneider's colleague Dean Hines of the Space Science Institute in Corrales, New Mexico.

That intense radiation indicates the presence of an unusually large amount of dust, Hines said.

The dust is heated by the light from its host star, "just like the dust on the light bulbs in my house [is heated]," Hines said.

"The fact that it's crashing into the interstellar medium really lit this disk up and allowed us to see it."

The scientists were surprised that there was enough interstellar gas and dust to produce this effect, because our region of the galaxy is generally believed to be relatively gas free.

Apparently, Schneider said, that's not true. "That needs following up," he said.

Stellar "Quadruplets"

At the same meeting, University of Hawaii researcher Evgenya Shkolnik reported another odd finding: a unique quadruple star system that packs four stars into a region smaller than the orbit of Jupiter.

The stars are grouped into two closely spaced pairs, 12 and 50 million miles (20 and 80 million kilometers) apart, respectively.

"It's really quite amazing that four stars all orbit each other at this distance," Shkolnik said.

It's not possible for all four stars to have formed that closely together, she said.

Rather, they must have formed at greater distances and then spiraled together as interstellar gas slowed their orbits.

The gas is now gone, leaving the stars, Shkolnik explained.

"There is no reason to believe that the system is actually young," she said, but the stars must have moved close together within the first 100,000 years or so of their lives.

"Because soon after, within the first 300,000 or 400,000 years, the gas all dissipates," she said.

The two pairs revolve around each other about once every nine Earth years.

The star system lies near the constellation Aquarius, about 166 light-years from Earth.

Shkolnik found it while studying the spectra of small, dim, stars relatively close to Earth.

The newfound system seemed unusual because it appeared to emit four spectra superimposed on each other, she said.

"When I first looked at it, I was very excited, and confused," Shkolnik said.

While the system is unique among known stars, it probably isn't one of a kind. But Shkolnik said she doesn't know how common such systems might be.

"I can't really say more, because people haven't looked at this kind of high-resolution information for very many low-mass stars," she said.

Other astronomers will be studying the system intensely, she said, as they try to tease out more details of the stars' orbital interactions.

That will allow researchers to test theories of stellar evolution, she added.

"You'll certainly be hearing a lot about the system," she said. "There's a lot of potential for more science."

12-01-08, 19:43	#1 (permalink)
collarian Neptune Join Date: Nov 2004 Location: Mars Posts: 6,867 Credits: 7,728 Thanks: 1,809 Thanked 2,516 Times in 981 Posts	Flying "Moth" Star, Stellar Quadruplets Discovered Astronomers studying our corner of the galaxy have found a strange object that looks like a moth spreading its wings and a never before seen system of four tightly grouped stars. The first of these phenomena, dubbed the Moth, is a disk of dust and gas illuminated by a young star in the constellation Puppis. Such disks, believed to be made of the material from which planets form, are common around young stars. But this one is oddly bent, as though flying into a headwind, and that's exactly what it's doing, said Glenn Schneider of the University of Arizona. Schneider was part of a team that took infrared images of the object with the Hubble Space Telescope. "Dust grains normally orbit in a plane unless they're disturbed by something," he said yesterday at a meeting of the American Astronomical Society in Austin, Texas. But in this case, he said, the star and its disk are plowing through an interstellar gas cloud. "That produces a local wind that is blowing the dust backward, producing this meniscus-like [or crescent] shape," Schneider said. "Intense Radiation" The Moth was found as part of a systematic search for planet-forming disks that might shed light on how planetary systems, including our own, formed. About 112 light-years from the sun, the Moth was detected because of the intense infrared light it emits. "One of the things that drew us to this star system is how bright it is in the infrared," said Schneider's colleague Dean Hines of the Space Science Institute in Corrales, New Mexico. That intense radiation indicates the presence of an unusually large amount of dust, Hines said. The dust is heated by the light from its host star, "just like the dust on the light bulbs in my house [is heated]," Hines said. "The fact that it's crashing into the interstellar medium really lit this disk up and allowed us to see it." The scientists were surprised that there was enough interstellar gas and dust to produce this effect, because our region of the galaxy is generally believed to be relatively gas free. Apparently, Schneider said, that's not true. "That needs following up," he said. Stellar "Quadruplets" At the same meeting, University of Hawaii researcher Evgenya Shkolnik reported another odd finding: a unique quadruple star system that packs four stars into a region smaller than the orbit of Jupiter. The stars are grouped into two closely spaced pairs, 12 and 50 million miles (20 and 80 million kilometers) apart, respectively. "It's really quite amazing that four stars all orbit each other at this distance," Shkolnik said. It's not possible for all four stars to have formed that closely together, she said. Rather, they must have formed at greater distances and then spiraled together as interstellar gas slowed their orbits. The gas is now gone, leaving the stars, Shkolnik explained. "There is no reason to believe that the system is actually young," she said, but the stars must have moved close together within the first 100,000 years or so of their lives. "Because soon after, within the first 300,000 or 400,000 years, the gas all dissipates," she said. The two pairs revolve around each other about once every nine Earth years. The star system lies near the constellation Aquarius, about 166 light-years from Earth. Shkolnik found it while studying the spectra of small, dim, stars relatively close to Earth. The newfound system seemed unusual because it appeared to emit four spectra superimposed on each other, she said. "When I first looked at it, I was very excited, and confused," Shkolnik said. While the system is unique among known stars, it probably isn't one of a kind. But Shkolnik said she doesn't know how common such systems might be. "I can't really say more, because people haven't looked at this kind of high-resolution information for very many low-mass stars," she said. Other astronomers will be studying the system intensely, she said, as they try to tease out more details of the stars' orbital interactions. That will allow researchers to test theories of stellar evolution, she added. "You'll certainly be hearing a lot about the system," she said. "There's a lot of potential for more science." __________________

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
"Clemente" Sarmorabiye Teame Tahe Jadvaliye "Mursia" Shod	MehdiBaTo	Soccer	3	07-03-08 08:37
"Bahram Radan" Dar Filme Kargardane Amrikayei, "Molana" Mishavad	MehdiBaTo	News	0	02-01-08 09:19
Jalili: "Onvane "Khalije Doosti" Negahe Rahbordiye Iran Ast"	MehdiBaTo	News	0	30-12-07 08:59
Eliyase Seriale "Eghma" Be Didane "Afshin Ghotbi" Raft!	MehdiBaTo	Soccer	1	04-11-07 12:08
Davat Az "Omar Sharif" Va "Michael Keene" Baraye Bazi Dar Filme San-Petersburg	MehdiBaTo	News	0	02-11-07 02:37