A Red Dwarf's Life!

Look at the night sky. What do you see? If the weather is suitable, you would see numerous stars illuminating the sky and a moon! But has it ever questioned you how these stars are created?

Firstly, let's go way back in time, during the begin of the universe. During the Big Bang, when the universe was first formed, 2 main elements were formed. Hydrogen and Helium alongside Lithium and Beryllium were created. These were the lightest elements to be formed during the Big Bang.

From here, all these elements sit in clouds known as molecular clouds or nebula's. These clouds are comprised of hydrogen atoms and a bit of helium atoms with small amounts of lithium and beryllium.

With the cloud of mass, there is pressure withing the cloud. The pressure in these clouds create turbulence which result in creating knots. These knots have enough mass that the clouds can collapse under it's own gravitational pull! This knot now pulled in by gravity is called a protostar.

From here, the gravity starts heating the core eventually beginning nuclear fusion. Nuclear fusion in short is the result of high heat and pressure fusing hydrogen into helium! For atoms to start fusing, the core has to be at 15,000,000 Kelvin. Once nuclear fusion has begun, as star is born!

As you know, our Sun has a gravitational pull, keeping our planet along with all the other bodies in our solar system in it's orbit! But, why doesn't the Sun's own gravitational pull make the it collapse on itself?

There is a repelling force that counters gravity and that is the energy output of nuclear fusion. When fusion occurs, there is 700,000,000 tonnes of hydrogen converted into 695,000,000 tonnes of helium. During this time, the 5,000,000 tonnes of energy release power the star, creating a barrier stopping gravity from crushing the star.

Now, the fate of the star is dependent on the size of the star. Firstly, we have the low mass stars. Like all stars, they also fuse hydrogen into helium to make sure gravity doesn't crush it's core. In red dwarfs', the core is small and the gasses inside are convective. This means that when hydrogen and helium atoms heat up, they rise to the top. Here, they cool down and make their way back down.

An important thing to remember is that when the hydrogen atoms and helium atoms come back down, only the hydrogen atoms are fused as they star is not hot enough to undergo helium fusion. This means that low mass stars live for a long time as they burn fuel at a slower rate relative to stars with a higher mass.

Like all stars, the red dwarfs' life will cease as there will be no more hydrogen for the star to fuse. In theory, after the red dwarf dies, it will become a black dwarf. This is in theory as red dwarf stars live for a very long time and the universe is simply not old enough to contain any of them which have died.

This is just the life of a Red Dwarf star. There are other ones such as the Red Giant which is a stage of life of the White Dwarf. Massive stars can also have the ability to turn into Neutron Stars which are one of the densest materials in the universe alongside a Black hole. A Black Hole's is so dense that gravity becomes incredibly strong! Because of this strength, even light can't escape meaning we can't see it.

But all these will be interested in another story! My next story will cover the Sun's life, the White Dwarf!

Sources:

https://www.youtube.com/watch?v=jfvMtCHv1q4&t=458s

A big thanks to the YouTube channel CrashCourse as they provided me with a lot of information!

I think this was a source:

https://www.universetoday.com/tag/red-dwarf-stars/

Not too sure if this was a source:

https://imagine.gsfc.nasa.gov/science/objects/stars1.html#:~:text=Stars%20on%20the%20main%20sequence,phase%20of%20the%20star's%20life.&text=While%20the%20core%20collapses%2C%20the,the%20star%20to%20expand%20outward.

I think this was a source:

http://scienceline.ucsb.edu/getkey.php?key=4017#:~:text=Answer%205%3A,energy%20corresponds%20to%20higher%20temperatures.

Not sure if this was a source:

https://www.universetoday.com/145940/in-the-far-future-the-universe-will-be-mostly-invisible/