In life cycle , star go through different stage like protostar , main sequence , and red /blue dwarf.

Lets explore more about it.

• formation of star
  • Brown dwarf
  • Lower mass star ( F , G ,K ,M)
  • Heavy mass star ( O,B,A)
• Life of star
  • lower mass star ( F, G, K, M )
  • Heavy mass star ( O, B, A )
• Death of star
  • black hole / neutron star
  • white drawf

Formation of Star

You are looking at the remnants of a stars, having gas and dust used to form stars.

With time it form dense region and then gravity start attracting more matter.

Its first form like planets(Jupiter) then with the addition of more mass, the temperature and pressure in the core start increasing.

About 90% of star mass are at its core.

The star in this stage is know as protostar.

Now, after this star form one of the 3 objects on the basis of mass.

1. Brown dwarf
2. lower mass star
3. high mass star

Brown dwarf

Due to low mass it isn’t able to reach preassure and temperature in core to start nuclear fusion (what it is?).

In our own galaxy they are billions in number eventhough they are harder to find as they only emit infrared light.

They have a tendency to form star in future when it get enough mass.

Lower mass star(F, G, K, M)

You found this star in F, G, K, and M in standard classification ,They have very long life of up to a trillion year, They are very dim and most of them red in color.

LIFE

In stars cores 4 Hydrogen fuse to form 1helium releasing heavy amount of Energy.

This energy work against gravity to maintain stability .(why?) as star’s gravity is very strong it easily overcome the particle-particle repulsion.

As you know more proton in nucleus more tough is fusion is (why?)

production drop, now gravity starts domain crushing the core increasing the pressure.

With increase pressure fusion of Helium starts producing energy lower than hydrogen , producing more energy than earlier.

Due to higher energy star expand and become brighter and cool .

You also know with time helium also used and same above process happen with helium to produce beryllium and lithium and star more expand.

It continue to produce boron ,carbon and with increased energy and cool surface ,star now go through Red Giant , in this stage it’s size increase about 50 times.
oh … at this stage our sun’s surface touch earth .

It starts depleting its outerlayer like a ripping fruit.

At last stage Carbon, Oxygen, Nitrogen these form in core which release so much energy due to which its most of the layer other than core released into space ,

Remember gravity still working it compress the core to form white dwarf.

Released matter is called a planetary nebula, because of misunderstanding that it is planet
This nebula provide raw material for future star and planet.

White Dwarf

You find that all the white dwarf are  very compact so much that if you convert sun into white dwarf it about the size of earth.

In white dwarf all the intermolecular space are filled because of strong gravity , the electron-electron charge repulsion stop further collapse.

White dwarf release light trap inside it (which form when it was star), due to it’s heavy density it take about a million -5million year to escape light from it’s core.

With time they release all of it’s core energy and become dark.(a black dwarf ),we didn’t find any black dwarf because not enough time had gone to form it.

also one thing left to know.
That with a long time particle convert (decay or fuse) to form iron (most stable element) and all black dwarf covert into a giant iron ball.

Massive star( O, B, A)

They are white, blue in color have  mass between 8 solarmass – 256 solar mass .

more fatty a person is , shorter its life .

There life span is shortest of all other star of about few billion year.

The most massive s22tar found is R136a1 (2020)

Their mass produce high pressure in core , also its core is bigger than lower mass star due to which their fusion is faster than lower mass star, producing lots of energy.

lifeSpan

They also have same process as lower massive star but much faster and also it’s process won’t stop after formation of Oxygen, Nytrogen, Fluorine, it forced by gravity to continue its formation till iron form.

(If same why to read it again )

EndTime

Iron is nuclear ash , it’s fusion not produce any energy  and now gravity starts crushingit, as no energy left to resist it.

(let’s go through step-by-step)

Particle starts coming closer and nuclear of atom starts occupy it’s electron (as earlier it is in plasma state) release energy in form of electron magnetic wave .

Atoms starts coming closer and closer until  electron-electron repulsion resist gravity. At this stage core become a white dwarf .

but … but gravity is still stronger than electron repulsion.

crushing continue, nucleus forced to come closer , due to electron repulsion ,electron fall in nucleus and neutralize proton to form neutron

(don’t think neutron is made up of electron and proton)

nucleus come closer until neutron – neutron particle repulsion resist gravity , it form a neutron star (most perfect rigid body).

The above two process release so much light and energy and also shockwave due to  sudden formation of rigid surface (neutron star) in  core , leads to the universe biggest explosion of supernova.

You are  looking  at the supernova.

really beautiful !

It releases most of the star mass to space making a beautiful nebula and it’s core form a neutron star

now if neutron star mass is more  than 3.4 solar mass.

then gravity is still able to overcome strongest known particle repulsion of neutron-neutron and crushing continue to form black hole( final stage)

Thats all our topic , which part you like the most and going to research more about it comment below.

If you have any query related to topic and have any suggestion comment  below, we will answer.

Neutron Star