We all know stars age and die over a course of several billion years. Our sun is expected to meet its fate in some 10 billion years, but what might happen after those final moments has always been a point of debate.
Now, an international team of astronomers, including Professor Albert Zijlstra from the University of Manchester, believe they have figured it out – and it ends in a blaze of glory known as a planetary nebula.
“When a star dies it ejects a mass of gas and dust — known as its envelope — into space,” Professor Albert Zijlstra of the University of Manchester explains in a statement. “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 and before finally dying.”
Planetary nebulae are how 90% of all stars die as they collapse from red giants to white dwarfs – but it was not previously clear if our sun had enough mass to create one.
By developing a new kind of stellar data model, the team tried to plot out the sun’s final act. The model predicts the brightness of our sun’s planetary nebula based on the age and luminosity of other stars’ gaseous envelopes. Though scientists had long assumed that our sun wasn’t massive enough to form a planetary nebula, the team showed it is in fact a possibility.
The team’s models show that stars like our sun, although lower in mass compared to many others, can get really hot very quickly, even as it dies. This would mean that our sun could still eject gasses and dust to make a visible planetary nebula.
“We found that stars with mass less than 1.1 times the mass of the sun produce fainter nebula, and stars more massive than 3 solar masses brighter nebulae, but for the rest the predicted brightness is very close to what had been observed,” Zijlstra adds.
The research was published in the journal Nature Astronomy