How stars are made?

Stars are the one celestial object in the sky that has always fascinated all of humanity.

According to our knowledge, the oldest accurately dated star chart was the result of ancient Egyptian astronomy in 1534 BC.

The earliest known star catalogs were compiled by the ancient Babylonian astronomers of Mesopotamia in the late 2nd millennium BC.

The spark we hold for these gaseous balls of light still burns bright all through science, literature and so much more.
 
The first question that pops up, is how does science define stars?

A star is an astronomical object consisting of a luminous spheroid of plasma held together by its gravity.

In the simplest terms, a star is a very large ball of bright glowing hot matter in space.

That matter present is called plasma These matters are held tightly together by gravity and they emit large volumes of heat and light. 
 
Now that we know what a star is, we need to delve into how they are made.

The fundamental of understanding anything, especially astronomical objects, is in finding out the formation and origin of the object. 
 
A star is born when atoms of light elements are squeezed under enough pressure for their nuclei to undergo fusion.

Let us understand one element of this basic statement. Atoms of light elements are the basic building blocks of the sun.

The atoms furthermore have nuclei, that is the small, dense region consisting of protons and neutrons at the center of an atom.

Stars are formed when the atoms of the star go through a process called Nuclear fusion.

Nuclear fusion is the process by which two or more atomic nuclei join together, or “fuse,” to form a single heavier nucleus.

This leads to the production of large amounts of energy during the whole process. 
 
Stars are the result of a balance of forces.

The fusion begins when the forces of gravity compress atoms in interstellar gas which exerts an outward pressure.

Stars remain stable in their form as long as the inward force of gravity and the outward force generated by the fusion reactions are equal.

The balance of these forces makes for one of the most beautiful celestial bodies in our universe.
 
It is important to break down the whole process to have a deeper understanding of the transformation of a nebula to a star.

Our galaxy and other galaxies in the current universe are famous for their cloud of gases floating around.

These clouds have been named nebulae.

The size of a nebula is around many light-years across and contains enough mass to create several thousands of celestial bodies the size of our sun.

Nebulae mostly consist of an overwhelming amount of hydrogen and helium molecules.

However, most nebulae also contain atoms of other elements, as well as some surprisingly complex organic molecules.

These heavier atoms present are the remnants of old stars.

These stars have exploded in an event we call a supernova.

These supernovas are the explosion that occurs at the end of a star’s life cycle.

The source of the organic molecules is still a mystery.
 
The gas molecules end up getting pulled together due to Irregularities in the density of the gas.

These are caused by net gravitational forces.

Some astronomers are of the strong belief that a nebula collapses when there is a gravitational or magnetic disturbance.

An increase in temperature is the result of the gases collecting. During this process, they lose potential energy too.

The temperature keeps accelerating as the collapse continues.

Quite frequently the collapsing cloud separates into many smaller clouds.

Each of these clouds may eventually become a star of its own.

It has been noticed that the core of the cloud always collapses faster than the outer parts.

Another observation is that the clouds begin to rotate faster to conserve angular momentum

This is normally determined by the inertia and angular velocity of the body.
 
The molecules of hydrogen gas start breaking apart as the core reaches a temperature of 2000 degrees.

They break into hydrogen atoms.

As the core reaches the temperature of 10,000 degrees Kelvin, the body slowly begins to look like a star. This occurs when the fusion reactions begin.

When it has collapsed to about 30 times the size of our sun, it becomes a protostar.

A protostar is a name given to the early formational stages of a star.
 
When the pressure and temperature in the core become great enough to sustain nuclear fusion, the outward pressure acts against the gravitational force. The core has reached approximately the size of our sun now.

The dust that remains ends up enveloping the surroundings as the star heats up.

It glows brightly in the infrared part of the spectrum. At this point, the visible light from the new star cannot penetrate the envelope. Eventually, the star begins its rotation.

The properties and lifetime of the star depending on the amount of gas that has remained trapped inside.

A star like our sun has a lifetime of about 10 billion years and is just middle-aged, with another five billion years or so left.
 
After some time, the temperature gets so extremely high at the center.

This triggers a fusion reaction. All the material that has fallen in then evolves into a hot, bright star.

This new star will continue to shine as long as there is hydrogen gas to fuse through nuclear reactions and the gravitational pressure pushing inward keeps the atoms very hot and tightly packed at the center.