Life and Death of a Star

By: Tsegazeab Beteselassie



Hypernova: This is an artists representation of a hypernova.
Picture is from:scitechdaily.com 

On a clear night, if you ever had looked at the sky, you will see stars scattered through the sky. We should know about them, because their death made our sun, and eventually, us. Our sun was created from dust clouds in the night sky, which were the remains of dead stars. The clouds were, in turn, made by supernova explosions. But lets rewind to the moment a star was born.

 

    We will start with a dust cloud, floating through the sky. The molecules' gravity will attract one another. Soon, the dust clouds will compress into a dense mass of hydrogen and helium. The pressure will get the compressed mass very hot. However, if fusion never starts, it will turn into a brown dwarf, nicknamed 'false stars'. However, if fusion starts, then a star will be born. Fusion will eat up the stars mass, making hydrogen into helium by fusing them together. Fusion happens when the pressure of the star will overcome the repulsion between atoms, and smashes them together at high speed. This process will continue for millions, billions, or even trillions of years, depending on the star's mass. But, you may ask, eventually the star will run out of fuel to supply fusion. Then what happens?*

 

 particular element. But meanwhile, the star will continue the fusion. Suddenly the star will start to flare up again, this time bigger than before. The reason for this is because the star ran out of helium to continue fusion. The flare gets the star even hotter, so it can fuse lithium into the next element. So this process continues for a while. Until, of course, it has to fuse the particular element I was talking about.

Fusion: This is an artists representation of fusion.
Picture is from:news.discovery.com 

   After the star is done converting hydrogen into helium, what happens next? Well, the answer is this. The star flares up. It becomes a red giant. The star will get even hotter, ending up in the star converting helium into the next element, lithium. The star contracts, and the star keeps on fusing atoms. But this will eventually spell doom for the star. The reason why is that as you go down the periodic table of elements, the star has to get hotter and hotter to sustain fusion. The star will eventually not be able to get hot enough to sustain fusion. But what element is so tough, that even stars can not fuse it?

 

    This element is one we use all the time, a very popular element on earth. It is iron. Iron is one of the most withstanding element created. Even the stars' furnace can not fuse iron. Now in the star is a big problem. As soon as the star was born, two rivals started to fight. They were fusion and gravity. Gravity wants to crush the star, and fusion wants to blow it up. The match has been even, so the star is stable. But when fusion falters, gravity takes over, crushing the star. But soon, the star is packed so tightly, that the energy rebounds, and creates one of the most powerful explosions in the universe. A supernovae**.

 

    The star explodes, and creates a monstrous dust cloud and maybe a neutron star or a black hole. In the explosion, it is so hot that all the heavier elements are formed in a flash of light. Eventually after millions of years, another star is formed, starting the cycle again. So now you know where those beautiful stars came from. They came from a supernovae.

 

* Actually, ordinary stars like our sun usually stop there, to make a nebulae and a white dwarf.

** However, hypernova are more powerful. But they can be classed as a type of supernovae.

 

Email me at tsegazeab12@outlook.com or tsegazeab12@gmail.com. Thank you and subscribe!