Australasian Science: Australia's authority on science since 1938

Dying Stars Leave Dusty Trails

By David Reneke

News from the space and astronomy communities around the world.

David Reneke is an astronomy lecturer and teacher, a feature writer for major Australian newspapers and magazines, and a science correspondent for ABC and commercial radio. Subscribe to David’s free Astro-Space newsletter at www.davidreneke.com

The full text of this article can be purchased from Informit.

Stars get pretty sloppy towards the end of their lives and the nuclear fuels start to run out. The star pulsates, expanding and contracting like a fish just out of the water. Each pulse belches out globs of gas into space that eventually get recycled into a new generation of stars and planets. The universe thought about recycling long before we came along.

But there’s a puzzle – accounting for all that lost material is difficult. Like trying to see a wisp of smoke next to a stadium spotlight, observing these tenuous sheets of stellar material swirling just over the surface of the star is considerably challenging.

But by using an innovative technique to image starlight scattering off interstellar grains, astronomers have finally succeeded in seeing ripples of dust flowing off dying stars.

The three study stars, W Hydra, R Doradus and R Leonis, are what astronomers call red giants – stars that are no longer fusing hydrogen in their cores but have moved on to forming heavier elements. Each is completely enveloped by a very thin dust shell, most likely made up of minerals, allowing atoms to start sticking together to form more complex compounds.

Minerals like these will go on to seed asteroids and possibly rocky planets like the Earth in the continual cycle of death and rebirth playing out in the galaxy. It’s probably been going on since time...

The full text of this article can be purchased from Informit.