Stars well-endowed with gold have fewer companions

Nov 08, 2007

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 the Planetary Science Institute at ANU. “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:
arxiv.org/abs/astro-ph/0612172

Source: Australian National University

Explore further: NASA telescopes set limits on space-time quantum 'foam'

Related Stories

Water was plentiful in the early universe

May 13, 2015

Astronomers have long held that water—two hydrogen atoms and an oxygen atom—was a relative latecomer to the universe. They believed that any element heavier than helium had to have been formed in the ...

Hubble Finds Giant Halo Around the Andromeda Galaxy

May 07, 2015

Scientists using NASA's Hubble Space Telescope have discovered that the immense halo of gas enveloping the Andromeda galaxy, our nearest massive galactic neighbor, is about six times larger and 1,000 times ...

Chemical fingerprints of ancient supernovae found

Mar 23, 2015

A Carnegie-based search of nearby galaxies for their oldest stars has uncovered two stars in the Sculptor dwarf galaxy that were born shortly after the galaxy formed, approximately 13 billion years ago. The ...

Recommended for you

NASA telescopes set limits on space-time quantum 'foam'

12 hours ago

A team of scientists has used X-ray and gamma-ray observations of some of the most distant objects in the universe to better understand the nature of space and time. Their results set limits on the quantum ...

Shining message about the end of the Dark Ages

14 hours ago

An international team, including researchers from the Centre for Astronomy of Heidelberg University (ZAH), has discovered three "cosmic Methusalems" from the earliest years of the universe. These unusual stars are about 13 ...

The kinematics of merging galaxies

15 hours ago

The unprecedented sensitivity of space telescopes has powered a revolution over the past decade in our understanding of galaxies in the young universe during its first billion years of existence. These primitive ...

Hubble video shows shock collision inside black hole jet

May 27, 2015

When you're blasting though space at more than 98 percent of the speed of light, you may need driver's insurance. Astronomers have discovered for the first time a rear-end collision between two high-speed ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.