ANU research: age of stars could unlock secrets of the universe

Discovering the age of stars using a new research technique may help build a much better understanding of the history of the universe, a Canberra scientist says.

An international team led by Australian National University astronomer Luca Casagrande has pioneered a research method that uses observations of stars' brightness and sound waves that pulsate through them.

Dr Casagrande said sound waves pulsated through stars, causing them to regularly grow slightly bigger and cooler, a process that changed their brightness.

Other researchers had observed the pulsations to understand the physics of individual stars and identify the planets in front of them, he said.

His team had looked at several hundred stars and used the information they gathered to determine when the stars were formed.

His technique is set to improve scientists' understanding of how the Milky Way formed and evolved, and may uncover evidence of a violent past, including collisions with other galaxies.


''With this technique you can really put what you see in the sky on a time line and understand the major events which brought things to appear in the way they appear today,'' he said.

Dr Casagrande said he had measured stars aged from half a billion years old to about 14 billion years old. ''When we look at them, it's like we are looking at the fossils of the epoch at which those stars were formed.''

The new technique enables astronomers to date stars with a precision of between 10 per cent and 15 per cent, a very good success rate given their age, Dr Casagrande said.

The research team's findings have been published in the preprint of the latest issue of The Astrophysical Journal.