What are Black Holes ?

"The Black Holes of nature are the most perfect macroscopic objects there are in the Universe : the only elements in their construction are our concepts of Space and Time".


This universe always leaves our minds with all mysteries. And when it comes to mysteries, then of course we must talk about BLACK HOLES - One of the most iconic topics of physics. Black holes have an interesting history and may have a long-lasting future. Now let’s get started… 


Black holes are the places in the universe where one can find an enormous amount of gravitational pull, to be exact-infinite. Even light can’t escape from its pull which shows the strength of its gravitational pull. It can squeeze anything into nothing which once again tells us about its strength. 

These enormous monsters are invisible and can’t be seen with naked eyes but can be observed with powerful telescopes.  These monsters are the results of the dead stars and this was predicted by General Relativity their proposed  Albert Einstein.  During the death of a massive star, it leaves a “dense remnant core” . If the mass of this core is more than 3 times the mass of our Sun, it will end up producing a Black Hole.

NASA's Neil Gehrels Swift Observatory imaged rings of X-ray light centered on V404 Cygni, a binary system containing an erupting black hole (dot at center), with its X-ray Telescope from June 30 to July 4, 2015. The dark lines running diagonally through the image are artifacts of the imaging system. 

Credits : https://universe.nasa.gov

How do we know their presence ? 

As told before, Black Holes are invisible and can’t be detected so easily with telescopes which can detect X-ray, light and other forms of electromagnetic waves. These monsters have to be observed for some time to know their presence by observing the activities of stars and other interstellar matter which are nearby to them. Black Holes suck in the matter nearby them by a process called “ACCRETION”. The attracted matter gets heated up which results the Black Holes to show off some signals by their emissions of X-ray into space. The recent studies have also proven that they do emit gamma ray bursts. 

How do these monsters form ? 

When a star runs out of fuel(Hydrogen) to perform thermonuclear fusion, the star ends up collapsing because of its own mass and leaves out a dense remnant core. If this star has a mass of 2 to 3 solar masses, probably we can expect a “Birth of a Black Hole”. This means that the death of a star is the birth of a Black Hole. These Black Holes have different types which depend on their size and mass. 

Types of Black Holes 

Basically there are 3 types of Black holes and they are:

Some cosmologists suspect the 4th type of Black Holes called “Primordial Black Holes” which might have formed very soon after the birth of the universe .

Stellar mass Black Holes

It is estimated that the stars with 20 times the Sun’s mass may end up with the birth of the Stellar Black Holes. The mass of these Black Holes are estimated to be more than 100 times the mass of our Sun. These stars can gain more mass by the collisions with other stars and Black Holes. The Stellar mass Black Holes which are found so far are paired with stars which made it a little bit easy to figure them out. In some cases called X-ray Binaries , the black pulls of the gas from the star which gets into its accretion disk and gets heated up, resulting in the emission of X-rays. Nearly 50 Stellar mass Black Holes are revealed by these circumstances in our galaxy. But scientists suspect nearly 100 million of these Black Holes just in our Milky Way. 

Images of the milky

Credits :https://www.nasa.gov/ 

Supermassive Black Holes 

Supermassives can be found in the centres of every galaxy and we do have one in our Milky way called Sagittarius-A. These blacks have their masses ranging from tens of thousands to billions of times the mass of our Sun. Our Sagittarius-A have a mass of 4 million times the mass of our Sun. This number might look so big but comparatively is it smaller than other Black Holes found in other galaxies like TON -618 which is being the largest Black Hole with 40 billion times the mass of our sun. The birth of these Black holes still remains unknown and this makes it one of the interesting topics to search about Black Holes. It is estimated that these supermassive Black Holes would have formed after one billion years after the Big Bang. These Black Holes might have been formed by the supernova of the supermassive stars in the early universe , which might have been the starting point of these supermassive monsters.  These supermassive monsters may grow even bigger by feeding on other stellar mass matters and neutron stars. These Black Holes can merge to one another during the collision of 2 galaxies. 

Intermediate mass Black Holes 

These Black Holes still puzzle the minds of scientists with their no continual masses between these Black Holes and stellar and supermassive black holes. Scientists think that these are the results of the collision of 2 stellar mass Black Holes, where it keeps a check mate point - question… But still it is estimated that these Black Holes may have their masses around one hundred to hundreds of thousands of times the Sun’s mass or tens of thousands. Many of these Black Holes are identified but not yet confirmed because of the puzzling questions they leave behind. 

Primordial Black Holes 

These are theoretically said by the scientists but we have no proven evidence to show their existence. It is being estimated that these Black Holes might have formed in the very first second of the birth of our Universe. The mass of these Black Holes might range from 10^(-8) to more than ten thousand times the mass of our Sun. Scientists say that these Black Holes would have evaporated eventually in the course of time as theoretically, less massive Black Holes will evaporate more quickly than the massive ones. But still scientists do have hope on the ones which have more mass of these black holes, which could still survive in this Universe somewhere, far away. 

Hope that this article would have given you a good idea of Black Holes in short.

Thank you for reading this article…

Stay tuned with Black Hole of Knowledge…

Sourced from: www.nasa.gov 


An article by Zandriana

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