Will The Sun Become A Black Hole?

Black holes are some of the most mysterious objects in the known universe. Their existence was first discussed and debated by Albert Einstein and Schwarzschild during the desolation of World War 1.

Since then, the concept of black holes has transformed from an idea to something we have detected in reality, with the first real photograph of one being released in April 2019. 

Since the discovery that black holes are born from dying stars, there has been a lot of thought as to what kind of stars will become them – which begs the question – will our star, the sun, become a black hole? 

We’ve created this article to outline some of the most important features of black holes, as well as to explore what happens at different life stages of a star before we discuss whether or not our sun would become a black hole itself. There is also a handy FAQ section at the end of this article, to answer some of the more common questions around these strange, confusing, celestial objects. 

What Is A Black Hole?

A black hole is an area of space that has gravity so strong that nothing can escape it. Its name comes from the fact that nothing, not even light can escape it. Because of the ‘dark’ nature of them, not that much is known about Black Holes – only that they exist and that they have massive effects on space around them. 

Many galaxies have a supermassive black hole in their center – for example our own galaxy, which revolves around one we have named Sagittarius A. There are only theories as to what goes on over the ‘event horizon’ (the border from which no light can escape, and is therefore black to us). One of the more popular theories is that black holes have a gravitational singularity in their center – an area of space that is infinitely dense.

If the idea of infinite density is confusing – don’t worry! It has been confusing physicists for a long time now. A better way to explain what that means is to say it’s a great amount of matter – stuff – that has been packed into a very small area. For example, a black hole might be 24 times the mass of our sun, but only 10 miles in diameter. 

Gravitational Singularities, though predicted by general relativity, are believed by some physicists to not be possible. 

How Are Black Holes Created?

Most black holes are born from the pieces of a large star that ends its life in what is called a supernova explosion. To understand how a supernova explosion in space occurs, we first have to understand a little about the lifecycle of a star. 

All stars, just like our sun, will eventually die because they will use up all of their internal nuclear fuel. What happens after that completely depends on the mass of the star.

Once a large star has used up all of its fuel, it can collapse and its outer layers push out into space as a supernova explosion. These explosions are well observed by astronomers and could have first been observed by humans as early as 1000 BCE. In more recent times, supernovas 

At this point, two things happen – either the collapsed core of the star can continue to exist as a neutron star, or if there is enough mass, the star will collapse into a black hole. We have a lot more evidence of neutron stars than we do of black holes because neutron stars still give out light, whereas black holes do not. 

Is Our Star The Right Kind To Become A Black Hole?

The answer to whether or not our star, the sun, could become a black hole is no. Our sun could not become a black hole because it is too small. The size a star would need to be to have a chance of becoming a black hole is 2 to 3 solar masses (a measurement used to determine the size of stars). Our star is only one solar mass – so it’s very unlikely that it would become a black hole. Only stars with enough mass can explode into a Supernova.

That’s not to say that our sun is safe from eventually changing or ‘dying.’ All-stars in the universe will eventually burn out. Ours is thought to have around 10 billion years left in its lifecycle, so we don’t have to worry all that much! That said when it does eventually die it is most likely to become a Red Giant.

When Our Sun Becomes A Red Giant

A red giant is one of the many potential end-of-life scenarios for a star. After billions of years of reactions from the core of a star, it eventually becomes exhausted. When this happens our sun will burn helium and begin to expand. As it expands, its surface will cool and become red in color. At this point, we could call it a Red Giant. It will begin to expand and eventually swallow our Solar System – which includes earth! 

What happens after is difficult to say, and is something that has been debated by scientists for some time. It is very possible that after the sun has been a red giant for a billion years or so, it will slowly decrease in size and cool. Once it’s cool it will be a white dwarf – which is a small, very dense star that will radiate only a tiny percentage of its original energy.

Final Thoughts

We hope that this article has given you some insight as to what will happen at the end of our sun’s lifecycle. Generally, stars the size of our own are just not big enough to explode into supernovas and then collapse into neutron stars or black holes.

Our sun is far more likely to become a red giant which will expand and slowly destroy our solar system. This is likely to happen 5 billion years from now, long after humans are expected to be alive. Below is a short FAQ to explain some of the more complex terms used in this article that we missed.


What Is A Neutron Star?

A neutron star is a strange object in the universe that is composed of a very high density of mass but without much size. They are the densest objects in the universe that are not black holes. They occur in much of the same way a black hole does, the remnant of a gigantic star once it has exploded in a supernova. Neutron stars differ from black holes because they are composed mostly of neutrons. 

What Would Happen If Our Sun Was A Black Hole?

If our sun was a black hole, it wouldn’t suck up the entire solar system as might be expected. Black holes have incredible gravitational pull inside of their event horizon, but they don’t necessarily affect every planetary body next to them.

Much like now, if our sun was a black hole the planets would likely resume their normal orbit. The main difference in our solar system is that it would be very cold and the earth would likely freeze – so let’s hope our sun doesn’t get replaced with a black hole any time soon!

Gordon Watts