Andrew Yee[_1_]
November 9th 07, 11:05 PM
MARKETING AND COMMUNICATIONS DIVISION
AUSTRALIAN NATIONAL UNIVERSITY
CANBERRA ACT 0200 AUSTRALIA
For interviews:
Dr Charley Lineweaver, 02 6125 6717
Dr Daniel Grether, 0418629543
ANU Media Office:
Simon Couper, 02 6125 4171, 0416 249 241
Thursday 8 Nov 2007
Stars well-endowed with gold have fewer companions
The chequered destinies of Australian Idol winners underscores what
astronomers have known for a long time -- star formation is complicated.
A new astronomical study adds an unexpected twist to the complications:
stars well-endowed with gold and other heavy elements have fewer stellar
companions. Researchers from The Australian National University (ANU) and
the University of New South Wales (UNSW) believe their discovery could help
track down Earth-like planets outside of our solar system.
"Ten years ago researchers found that stars with a large amount of heavy
elements were more likely to be orbited by planets," said report co-author
Dr Charley Lineweaver from ANU's Planetary Science Institute. "We still
don't understand why, but that's the way it is. Our goal was to find out if
such high-metallicity stars might also be more likely to be orbited by other
stars."
The Sun is a typical star in that about one per cent of its mass is made of
heavy elements like oxygen, iron and gold. However, there are many stars
with as little as one third of a per cent of their mass in heavy elements,
while other stars have tens times that much. The amount of heavy elements
somehow plays an important role in the types of object that form around a
star.
Dr Lineweaver and Dr Daniel Grether from UNSW put together the most complete
census of nearby stars, including the amount of heavy elements in these
stars and whether the stars had planetary or stellar companions. They were
surprised when they found the opposite of what was expected -- stars with
the highest content of heavy elements were less likely, not more likely, to
have stellar companions.
"Our counterintuitive result does not yet have a good theoretical
explanation, but we think that stars that form in different regions of our
galaxy probably followed different paths to stardom," Dr Grether said.
Detecting Earth-like planets has become a hot field for astronomers. Dr
Lineweaver and Dr Grether believe that further research on the relationship
between the amount of heavy elements in stars and the types of stellar and
planetary companions orbiting them could assist in the search for worlds
like our own.
The study is published in the latest edition of the Astrophysical Journal:
http://www.journals.uchicago.edu/ApJ/journal/contents/ApJ/v669n2.html
A local link to a pdf of the published version of the paper can now be found
at
http://www.mso.anu.edu.au/~charley/publications.html
AUSTRALIAN NATIONAL UNIVERSITY
CANBERRA ACT 0200 AUSTRALIA
For interviews:
Dr Charley Lineweaver, 02 6125 6717
Dr Daniel Grether, 0418629543
ANU Media Office:
Simon Couper, 02 6125 4171, 0416 249 241
Thursday 8 Nov 2007
Stars well-endowed with gold have fewer companions
The chequered destinies of Australian Idol winners underscores what
astronomers have known for a long time -- star formation is complicated.
A new astronomical study adds an unexpected twist to the complications:
stars well-endowed with gold and other heavy elements have fewer stellar
companions. Researchers from The Australian National University (ANU) and
the University of New South Wales (UNSW) believe their discovery could help
track down Earth-like planets outside of our solar system.
"Ten years ago researchers found that stars with a large amount of heavy
elements were more likely to be orbited by planets," said report co-author
Dr Charley Lineweaver from ANU's Planetary Science Institute. "We still
don't understand why, but that's the way it is. Our goal was to find out if
such high-metallicity stars might also be more likely to be orbited by other
stars."
The Sun is a typical star in that about one per cent of its mass is made of
heavy elements like oxygen, iron and gold. However, there are many stars
with as little as one third of a per cent of their mass in heavy elements,
while other stars have tens times that much. The amount of heavy elements
somehow plays an important role in the types of object that form around a
star.
Dr Lineweaver and Dr Daniel Grether from UNSW put together the most complete
census of nearby stars, including the amount of heavy elements in these
stars and whether the stars had planetary or stellar companions. They were
surprised when they found the opposite of what was expected -- stars with
the highest content of heavy elements were less likely, not more likely, to
have stellar companions.
"Our counterintuitive result does not yet have a good theoretical
explanation, but we think that stars that form in different regions of our
galaxy probably followed different paths to stardom," Dr Grether said.
Detecting Earth-like planets has become a hot field for astronomers. Dr
Lineweaver and Dr Grether believe that further research on the relationship
between the amount of heavy elements in stars and the types of stellar and
planetary companions orbiting them could assist in the search for worlds
like our own.
The study is published in the latest edition of the Astrophysical Journal:
http://www.journals.uchicago.edu/ApJ/journal/contents/ApJ/v669n2.html
A local link to a pdf of the published version of the paper can now be found
at
http://www.mso.anu.edu.au/~charley/publications.html