For a while now, scientists have been doing all kinds of math on when & how our Sun will die and what will be the fate of the planets that’s dependent on this yellow star, including Earth – well… we may have an answer now.
A team of International astronomers along with Professor Albert Zijlstra from the University of Manchester have an answer – it will turn into a planetary nebula – a luminous bubble of gas and dust but a bit more massive.
We all know that Sun is a hot star that’s composed of Hydrogen and Helium that holds the entire Solar System together – due to the electric currents that it emits. Oh yes, the most important thing, if there was no Sun and if its not the way that it is, there would be no life on Earth. Every single natural phenomena that happens on Earth, our Sun has a major role in it. Like the seasons, oceans currents, weather, climate, auroras etc. Even our Moon plays its own part. But more on that later.
Here is how our Sun will die:
Every star dies eventually. It takes millions of years but they do die. Here is what happens, when a star runs out of hydrogen fuel, the upper layer starts to expands due to hydrogen fusion. This process turns the star to a red giant. So when this happens to our Sun, it will start swallowing each planet one by one – Mercury, Venus and it will get to Earth (the end line is just beyond the Earth’s orbit). Lucky for us(for some), humanity will cease to exist by then.
After this point, the core becomes hot enough to cause the helium to fuse with carbon. Then, the helium runs out of fuel expanding the inner core and cools down. This collapses and forms into white dwarf and eventually turning into a black dwarf over a period of time.
Note: There is also a possibility of Supernova, when the star’s mass is much more massive than the sun, but I am not going to discuss about that here because, its another interesting topic and it needs a post of its own!
When will our Sun die?
Its death is speculated to happen for about 5 billion years from now. It will expand about 250 times its current size.
As mentioned earlier, in the end, a star turns to a red giant, collapses to a white dwarf eventually resulting in planetary nebula (a glowing ring of gas and dust) – as illustrated above.
Scientists usually predict star’s fate using a model which now have been used to predict our Sun’s fate.
Professor Albert Zijlstra from the University of Manchester said, “When a star dies it ejects a mass of gas and dust – known as its envelope – into space. 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. 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.”