How black holes formed by dead stars

Black holes are the most mysterious and fascinating places of the universe where laws of space and time rewritten.

How black holes formed by dead stars

Black holes are one of the greatest mysteries of the universe. They rewrite laws of space and time. Inside a blackhole matter compressed into a point of infinite density where space and time also become infinite.

Its hard to detect them. We can't see a blackhole because even light cannot escape from it. Only they can find by observing moments of objects around it. Blackhole absorbs or force to change behavior of everything around its gravitational perimeter.

Every galaxy has a giant blackhole in their center. The nearest neighboring blackhole is named as Sagittarius A. It lies in the middle of the Milky way.


Who discovered black holes

Albert Einstein first predicted the existence of black holes and Karl Schwarzschild discover blackholes in 1916. American astronomer John Wheeler introduced "Black Hole" term in 1967.


Life cycle of stars

As we mentioned, To understand the formation of a blackhole we must have a basic understanding about the life cycle of a star. Because blackholes born after the death of a star.

Not just life on earth, everything in this universe has their own lifetime and a duty. They are also born and in the end they die and become something else. We believe stars and universe itself born from huge explosion called the bigbang theory. Even if it is not proved. That this is the most popular theory from all of them.


How stars formed

Black holes are born from stars. Stars made from large amount of hydrogen and helium gas. They form when giant molecular clouds known as nurseries experience gravitational collapse.

Inside the core of a star, the hydrogen atoms heated and compressed by huge amount of pressure and temperature. So it turns hydrogen atoms into helium by releasing large amounts of energy.


What Are the 4 Main types of stars

Considering their Colour, Temperature, Mass, Radius, Luminosity and Spectra, Stars can be classified into 7 different types according to the Hertzsprung Russell diagram. We can identify the 4 main types of stars according to its mass

  1. Brown dwarfs - Jupiter size hydrogen helium gaseous planets.

  2. Low mass stars

  3. Medium mass stars - size most likely to our sun

  4. High mass stars


How stars die

Medium mass stars have life span about 10 billion years. The gravitational force react against its nuclear fusion force to keep the balance of a star. Until this happens star will continue to burn its fuel. Once hydrogen and helium run out it collapse.


Black dwarf

Black dwarfs are small burned star which has low brightness and temperature. Small stars dies slowly by starting to fade and becomes black dwarfs after its hydrogen and helium burning. They fade and shrink until their remaining lifetime.


Red giant

White dwarfs also are burned stars with hot core. Medium mass stars such as our sun becomes fade until it becomes red and 400 times its original size because its gravitational force is lower than its nuclear fusion.

After nuclear fusion becomes lower it will shrink more than its original size. And will be spent as a white dwarf in their remaining lifetime until it becomes completely dark.



Supernova is an explosion of a star which deform stars of High mass. Supernova Only happens to stars which has mass greater than three times that of our sun.

Theses explosions release energy to universe as cosmic waves, heat, light and all types of other electromagnetic waves due to its nuclear fusion by leaving a neutron star or a blackhole.



Hypernova is a very energetic supernova only occur explosion of a largest high mass star.

After the supernova of a giant star, It leave heavy remnants from its core that is highly gravitationally unstable. Collapsing These remnant in to highly dense one piece become a black hole or a neutron star.


Types of Blackholes

There are there types of blackholes discovered so far. those are

  1. Stellar black holes
  2. Intermediate black holes
  3. Supermassive black holes


First Real image of a black hole

Team of astronomers start a project to capture image of a blackhole placing system of multiple telescopes around the world. It was successful and they published processed image in April 2019

First image of a black hole


  • Black holes are one of the greatest mysteries of the universe.

  • Blackhole are rewrite laws of space and time.

  • Density of a blackhole may reach upto infinite.

  • Black holes can only find or study by observing round objects.

  • A giant blackhole lies at the center of every galaxy.

  • Sagittarius A is the nearest blackhole to us.

  • Stars form giant molecular clouds known as nurseries.

  • Stars classifieds by Hertzsprung Russell diagram.

  • There are 4 main types of stars. Brown dwarfs, small stars, middle mass stars, high mass stars.

  • Stars dies becoming black dwarf, Red giant or a supernova.

  • Red giant stars become white dwarfs in the end.

  • Very energetic supernova known as a hypernova.

  • First clear image of a black hole was taken in April 2018 by team of international astronomers.

  • There 3 types of blackholes. which are steller, intermediate, supermassive black holes.