Surprise Factor in How Stars Die: Sodium

Surprise Factor in How Stars Die: Sodium

Andrew Fazekas

for National Geographic

Published May 29, 2013

The way that stars spend their last years is largely shaped by their sodium "diet," according to a surprising new study published on Wednesday.

The study could upend current theories about how some stars that are similar to our sun die and become the basic building blocks for the next generation of stars and planets.

According to existing stellar evolution models, sunlike stars—those that are similar in size and chemical composition to our sun—swell to become so-called red giants in their final stage of life, before losing their atmospheres in a spectacular bubble of gas and dust.

This fate awaits our own sun in four to five billion years, scientists say.

The final period in a sunlike star's life, when stars make their greatest contribution to the universe, is known as the asymptotic giant branch (AGB).

"They puff off all their outer layers of gas and dust, enriching and polluting the surrounding space," said Simon Campbell, an astronomer at Monash University in Australia and the co-author of the new study published in the journal Nature.

"This gas and dust gets recycled and goes into the formation of the next generation of stars, planets—and possibly even life."

But now astronomers have found that not all sunlike stars follow the same rules when it comes to the end of their life cycles, and that some can skip the AGB phase altogether.


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By: Andrea
Date: Thu, 2013-06-06 11:14