How will the Sun look after it dies Scientists have predicted what the end of our Solar System will look like, and when it will occur. The final act will not be witnessed by humans.
Astronomers believed it would become a planetary nubula, a glowing bubble of gaseous and dust. However, evidence suggests it is much larger.
In 2018, an international team of astronomers reversed the equation and discovered that a planetary nubula was indeed the most likely Solar body.
Based on the age of other objects within the Solar System, the Sun is approximately 4.6 billion years old. Astronomers have predicted that it will die in 10 billion years based on observations of other stars.
Of course, there are many other things that could happen along the route. The Sun will become a red giant in 5 billion years. While the core of the star will shrink in size, its outer layers will expand to Mars' orbit, engulfing the planet. It's possible it is still there.
One thing is certain, however: We won't even be here by then. If we don't find a way to get off of this rock, humanity will only have about one billion more years. This is because the Sun's brightness increases by approximately 10 percent each billion years.
Although it doesn't seem like much, this increase in brightness will bring an end to life on Earth. Our oceans will disappear and the surface of the Earth will be too hot to allow water to form. We will be as bad as possible.
It is what happens after the red giant that is difficult to pinpoint. Numerous studies have shown that the Sun's initial star must have at least twice the mass to create a bright planetary nucleus.
The 2018 study, however, used computer modeling to show that our Sun, just like 90% of other stars, is most likely shrink from a red giant into a white dwarf, and then end up as a planetary nubula.
"When a star is destroyed, it releases a mass of dust and gas known as its envelope into the universe. The envelope can contain as much as half of the star's total mass. This exposes the star's core. At this point in star's life, the star is running out of fuel and eventually turning off before dying," stated Albert Zijlstra, an astrophysicist from the University of Manchester, UK. He was also one of the paper's authors.
"It's only then that the hot core makes the envelope glow brightly for approximately 10,000 years, a short period in astronomy. This is why the planetary nucleus can be seen. They are bright enough to be visible from very far distances, measuring in the tens of thousands of light years. The star would have been too faint to see.
The team actually created a data model to predict the life cycles of different types of stars and determine the brightness of the planetary Nebula associated with different star masses.
The observable Universe is home to many planetary nebulae, including the Helix Nebula and the Cat's Eye Nebula.
Cat's Eye Nebula (NASA/ESA).
They are called planetary nebulae because they look similar to planets when they were first discovered by William Herschel late in 18th century.
Astronomers discovered something quite remarkable almost 30 years ago: The brightest planetary nuclei in other galaxies have approximately the same brightness. Astronomers can use this information to calculate their distance from other galaxies.
Although the data proved this to be true, the models did not. This has been frustrating scientists since the discovery.
"Older, lower mass stars should produce fainter planetary nubulae than younger, more massive stars." "This has been a source for conflict over the last 25 years," Zijlstra stated.
"While the data suggested that bright planetary nubulae could be formed from low-mass stars like the sun's, the models stated otherwise. Anything less than twice the mass of the sun would make a planetary nubula too faint for us to see.
This problem was solved by the 2018 models, which show that the Sun is just below the limit of mass for stars that can produce visible nebulas.
Even stars with masses less than the Sun's will not produce visible nebulae. Brighter nebulae will be produced by larger stars that are up to three times as massive as the Sun.
The predicted brightness for all stars between them is very similar to what we have seen.
Zijlstra stated, "This is an excellent result." "We now have a method to measure the presence stars of ages a few million years in distant galaxies. This is a range that is remarkably hard to measure. We also know what the Sun will do after it dies!"
The journal Nature Astronomy published the research.
This article was published in an earlier version in May 2018.