Artist's impression of a dusty disc around a red dwarf star.
Credit: NASA/JPL-Caltech/T. Pyle (SSC)
An accidental find of a collection of
young red dwarf stars close to our solar system could give us a rare
glimpse of slow-motion planet formation.
Astronomers from The Australian National University (ANU) and UNSW
Canberra found large discs of dust around two of the stars, tell-tale
signs of planets in the process of forming.
"We think the Earth and all the other planets formed from discs like
these so it is fascinating to see a potential new solar system
evolving," said the lead researcher Dr Simon Murphy, from the ANU
Research School of Astronomy and Astrophysics.
"However, other stars of this age usually don't have discs any more.
The red dwarf discs seem to live longer than those of hotter stars like
the Sun. We don't understand why," said Dr Murphy.
The discovery of objects like these two challenges current theories
about planet formation, said co-author Professor Warrick Lawson from
UNSW Canberra. "It suggests the planet forming process can endure a lot
longer than previously thought," he said
The red dwarves may also host planets that have already formed from the dusty discs, Dr Murphy said.
"I think a lot of telescopes will be turned toward them in the next few years to look for planets."
The giveaway that the red dwarves had discs around them was an
unusual glow in the infrared spectrum of the stars. Although the discs
were not observed directly, Dr Murphy said such close red dwarves
offered a good chance of catching a rare direct glimpse of a disc, or
even a planet, by employing specialised telescopes.
"Because they are fainter than other stars and there is not as much
glare, young red dwarves are ideal places to directly pick out recently
formed planets," he said.
Our ability to detect these dim stars has improved dramatically in
recent decades, revealing a wealth of information, said Professor
Lawson. "Less than 20 years ago, the notion that the nearest part of the
Galaxy would be littered with young stars was a completely novel one,"
he said.
"Most of these objects lie in the southern sky and thus are best
accessed by telescopes in the southern hemisphere, including those
operated by the ANU and Australia more broadly."
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