SAN DIEGO, Jan. 9 — Planet-hunters have found two new planetary systems, neither of them much like ours and one of them downright bizarre, researchers said Tuesday.
ONE STAR has two planets locked in harmonic orbits — one twice as fast as the other — while the second star’s satellites are huge, one of them so big that it challenges the very definition of a planet, the scientists said at the annual meeting of the American Astronomical Society.
While astronomers have found dozens of planets outside our solar system over the last five years, these two new systems are only the second and third with more than one planet orbiting a star.
LONG-TERM PROJECT
These discoveries are part of a long-term project to search for planets among 1,100 stars within 300 light-years of Earth, which in cosmic terms is fairly close. A light-year is about 6 trillion miles, the distance light travels in a year.
These two new systems initially fooled astronomers, who previously believed each star had only one possible planet in its thrall. The planets are not literally seen, but are detected by a characteristic wobble of the stars they orbit. The putative planets’ gravitational pull causes the wobble.
The sunlike star HD 168443, 123 light years away in the constellation Serpens, has two monster planets orbiting it, according to astronomer Geoffrey Marcy of the University of California at Berkeley and Paul Butler of the Carnegie Institution of Washington.
Both of these planets are big, but one is so huge that it makes the whole system “truly bizarre,” Marcy said in an answer to e-mailed questions.
TOO BIG?
“The outer companion (of this star) is so massive, between 17 and 40 times the mass of Jupiter, that it seems too large for a conventional planet,” Marcy said.
“We frankly don’t know what name to give it! Is it a planet or brown dwarf (a dim failed star) or something that formed in the protoplanetary disk, but gobbled an unusual quantity of gas in that disk?” Marcy said. “We simply don’t know.”
Want to learn more?
http://www.msnbc.com/news/513746.asp
------------------
-Administrator / Owner
"Everything was true. God was an astronaut. Oz really is over the
rainbow. ...and Midian is where the monsters live." -Nightbreed
ONE STAR has two planets locked in harmonic orbits — one twice as fast as the other — while the second star’s satellites are huge, one of them so big that it challenges the very definition of a planet, the scientists said at the annual meeting of the American Astronomical Society.
While astronomers have found dozens of planets outside our solar system over the last five years, these two new systems are only the second and third with more than one planet orbiting a star.
LONG-TERM PROJECT
These discoveries are part of a long-term project to search for planets among 1,100 stars within 300 light-years of Earth, which in cosmic terms is fairly close. A light-year is about 6 trillion miles, the distance light travels in a year.
These two new systems initially fooled astronomers, who previously believed each star had only one possible planet in its thrall. The planets are not literally seen, but are detected by a characteristic wobble of the stars they orbit. The putative planets’ gravitational pull causes the wobble.
The sunlike star HD 168443, 123 light years away in the constellation Serpens, has two monster planets orbiting it, according to astronomer Geoffrey Marcy of the University of California at Berkeley and Paul Butler of the Carnegie Institution of Washington.
Both of these planets are big, but one is so huge that it makes the whole system “truly bizarre,” Marcy said in an answer to e-mailed questions.
TOO BIG?
“The outer companion (of this star) is so massive, between 17 and 40 times the mass of Jupiter, that it seems too large for a conventional planet,” Marcy said.
“We frankly don’t know what name to give it! Is it a planet or brown dwarf (a dim failed star) or something that formed in the protoplanetary disk, but gobbled an unusual quantity of gas in that disk?” Marcy said. “We simply don’t know.”
Want to learn more?
http://www.msnbc.com/news/513746.asp
------------------
-Administrator / Owner
"Everything was true. God was an astronaut. Oz really is over the
rainbow. ...and Midian is where the monsters live." -Nightbreed