Scientists have discovered how and when our sun will die, and it will be epic

What will our sun look like after it dies? Scientists have made predictions about what the end of our solar system will look like and when it will happen. And the humans won’t be around to see the final chapter.

Previously, astronomers believed it would turn into a planetary nebula – a luminous bubble of gas and dust – until evidence suggested it would need to be a bit bigger.

An international team of astronomers turned it over in 2018 and discovered that a planetary nebula is indeed the sun’s most likely body.

The Sun is about 4.6 billion years old, depending on the age of other bodies in the solar system that formed around the same time. Based on observations of other stars, astronomers expect it to reach the end of its life in around 10 billion years.

There are other things that will happen along the way, of course. In about 5 billion years, the Sun is expected to turn into a red giant. The star’s core will shrink, but its outer layers will extend to the orbit of the star Mars, sweeping our planet. If he’s still there.

One thing is for sure: at this point we certainly won’t be there. In fact, humanity is only a billion years old unless we find a way out of this rock. Indeed, the luminosity of the Sun increases by approximately 10% every billion years.

It doesn’t seem like much, but this increase in luminosity would end life on Earth. Our oceans will evaporate and the surface will become too hot for water to form. We will be as smart as possible.

It’s what comes after the red giant that has proven difficult to identify. Several previous studies to find this for a fascinating planetary nebula forming, the protostar must be twice the mass of the Sun.

However, the 2018 study used computer modeling to determine that, like 90% of other stars, our Sun is likely to change from a red giant to a white dwarf and then end up in a planetary nebula.

“When a star dies, it ejects a mass of gas and dust – called an envelope – into space. The envelope can represent up to half the mass of the star. This reveals that the core of the star, which at this stage of the star lacks vital fuel, eventually dies out and before it finally dies, ”says astrophysicist Albert Zelstra of the University of Manchester in the UK, one of the authors of the article.

“Only then does the hot core cause the ejected shell to glow for 10,000 years – a brief period in astronomy. This is what makes the planetary nebula visible. Some are so bright they can be seen. They can be seen at very great distances of tens of millions of light years, where the star itself is too faint to be seen.

The data model created by the team actually predicts the life cycles of different types of stars, in order to determine the luminosity of planetary nebulae associated with different star masses.

Planetary nebulae are relatively common throughout the observable universe, with famous nebulae such as the Helix Nebula, Cat’s Eye Nebula, Ring Nebula, and Bubble Nebula.

Cat’s Eye Nebula (NASA / ESA)

They are called planetary nebulae not because they have anything to do with planets, but because when William Herschel I discovered it at the end of the 18th century, they were. Similar in appearance to planets seen through telescopes at this time.

Almost 30 years ago, astronomers noticed something strange: the brightest planetary nebulae in other galaxies all had roughly the same level of brightness. This means that in theory at least, by looking at planetary nebulae in other galaxies, astronomers can calculate their distance.

The data showed it to be correct, but the models contradicted it, which has troubled scientists since the discovery.

He added, “Older, low-mass stars are expected to produce much weaker planetary nebulae than younger, more massive stars. It has become a source of conflict over the past 25 years. Zijlstra pointed

“The data suggests that you can get a bright planetary nebula from low-mass stars like the Sun, and models said that wasn’t possible, anything less than double the Sun’s mass would make the planetary nebula too faint to be seen. “

The 2018 models successfully solve this problem by showing that the Sun is at about the minimum mass of a star that can produce a visible nebula.

Even a star less than 1.1 times the mass of the Sun would not produce a visible nebula. On the other hand, larger stars with a mass up to 3 times the mass of the Sun, will produce the brightest nebulae.

For all the other intermediate stars, the expected luminosity is very close to that observed.

“It’s a fantastic result,” Zigelstra noted. “We now not only have a way to measure the presence of billions of years old stars in distant galaxies, a remarkably difficult range to measure, but we also understood what the Sun would do on its own. Dead!”

Publish research in the journal natural astronomy.

An earlier version of this article first appeared in May 2018.