How the Sun is going to die

The Sun will die in 10 billion years. And when it does, it’s going to blow. What’s left of us will become a billowing bubble of dead starstuff.

A dramatic death is predicted for the Sun in 10 billion years time. An international team of astronomers predicts it will puff out in an enormous orb of luminous interstellar gas.

It’s the kind of explosion that produces what’s known as a planetary nebula.

According to the study in the science journal Nature Astronomy , our Sun will go the same way 90 per cent of all stars go.

It’s all just part of the cycle of life for yellow dwarfs such as our own. As it eats up all its fuel, it will expand into a red giant. Then, at the end, it will collapse into a white dwarf.

It’s that collapse that will spew clouds of debris into space.

Until now astronomers have agreed on the sun’s expected life span, but the nature of its death has been controversial.

Such planetary nebulae are among the most beautiful and striking objects seen by astronomers, some shining bright enough to be seen across distances of millions of light years.

But a star has to be above a certain mass to create a visible nebula. Until now it was thought our Sun was too light.

The new modeling shows that the Sun is just massive enough to end its life in glorious style.

Professor Albert Zijlstra, a member of the international team from the University of Manchester, said: “When a star dies it ejects a mass of gas and dust - known as its envelope - into space. The envelope can be as much as half the star’s mass. This reveals the star’s core, which by this point in the star’s life is running out of fuel, eventually turning off before finally dying.

“It is only then the hot core makes the ejected envelope shine brightly for around 10,000 years - a brief period in astronomy. This is what makes the planetary nebula visible.

“Some are so bright that they can be seen from extremely large distances measuring tens of millions of light years, where the star itself would have been much too faint to see.”

The scientists developed a new data model that predicts the life cycle of stars. It showed that after ejection of the envelope, dying stars heated up three times faster than was previously thought. This made it much easier for a low-mass star such as the sun to produce a bright planetary nebula.

This story originally appeared in news.com.au.