HONG KONG: A “serendipitous discovery” only 400 light years from Earth could challenge current theories on how planets form and even allow future astronomers to witness the birth of a solar system.
An unusual glow in the infrared spectrum of two young red dwarf stars in the Southern Cross and Centaurus constellations led astronomers from the Australian National University and UNSW Canberra to discover large discs of dust surrounding the stars.
These discs contained the raw materials from which planets formed, lead researcher Dr Simon Murphy, from ANU’s Research School of Astronomy and Astrophysics, said.
“We didn’t really expect to find them, we were actually searching for stars belonging to a completely different young group and by pure luck we stumbled across this group of interesting stars,” Dr Murphy said.
Circumstellar discs of dust and debris are born with a star and often disappear within millions years.
“Some of the dust and gas goes to form planets, some of it’s accreted onto the star and some of it’s blown away from the system by the star,” Dr Murphy said.
“Usually by 10 million years old, discs are very rare around stars because the planets have already formed.”
Dr Murphy said the stars his team found are believed to be about 16 million years old, hence their surprise.
It could be that these stars are much younger than the cluster around them but Dr Murphy believes it is evidence that dust discs linger longer around lower-mass stars.
