Types of Black Holes

 

TYPES OF BLACK HOLES

 

Modern science and technology has enabled scientists to increase their knowledge and deepen their research into the vast cosmos , this applies to black holes as well . Till date 3 types  have been discovered, those three types are :

1. Stellar black holes

2. Intermediate black holes

3. Supermassive black holes

At the end of this blog , you will learn about these types in the simplest manner possible and will also have commanding grasp over it . They are as follow :

 

1. Stellar black holes : Stellar black holes are the most common ones with their mass ranging within 100 solar masses (one solar mass is equal to the mass of Sun).

Birth : When a star runs out of fuel , energy production stops due to which the core collapses and results in a supernova explosion , blasting the outer layer of star into space. And if the core’s mass is more than few solar masses , gravity at the core continues crushing mass all together into a point with infinite density, forming a black hole . Stellar black holes are formed from stars 10-20 times bigger than the Sun.

Mass required to be classified as a stellar black hole : More than 10 times than the Sun and less than 100 times than the Sun.

Method to detect them : These black holes can be found easily using X-ray binary system , where the gas of a nearby star is being pulled by black hole which is heated to millions of degrees of Celsius producing X-rays. Then the gas is pulled by the black hole through an accretion disk.  Scientists have estimated that there are as many as 10 million to a billion such black holes in the Milky Way alone.

 Some examples of stellar black holes are :

(i) Cygnus X-1 : The first stellar black hole , Cygnus X-1 , was discovered in 1961 by Paul Murdin. Cygnus is found in constellation Cygnus which is 6,070 light years away. It is the heaviest known stellar black hole and is 14.8 times the mass of the Sun. Scientists have estimated that it’s event horizon spins more than 800 times per second.

(ii) M33 X-7 : It is a stelar black hole and it’s mass is about 9 times than the Sun. It is found in the Triangulum galaxy. It is about 2.7 million light years away from Earth. This black hole is 16 times more massive than Sun. It’s diameter is roughly 60 miles or 95 km. This black hole formed from a supergiant star when it ran out of fuel and collapsed into a black hole. Astronomers found this in 2007 because it glows brightly because of it’s super hot gas which spirals around the black hole, forming accretion disk.

Now moving on to the other types of black holes which are different from stellar black holes.

 2. Intermediate black holes : The name tells us that their mass varies between stellar and supermassive black holes. These black holes are very rare and difficult to find because they are smaller than supermassive black holes and aren’t much active.

Birth : Scientists don’t actually know how these black holes are formed because they are too massive to be formed by collapse of a star. There is a thought that these black holes form when multiple stellar mass black holes merge with one another , forming a single and a bigger black hole. These merges usually happen in crowded areas of the galaxy. If these type of black holes are in the same region , they can collide and form a supermassive black hole.

Location : An IMBH (Intermediate-Mass Black Hole) can be found near a galaxy’s center by its perturbation on a star orbiting around the supermassive black hole.

Mass required to be classified as an IMBH : 100 to 1 million times  more massive than the Sun.

Some intermediate black holes are :

(i) G1 : G1 is a big cluster of about 12 million stars orbiting the center of Messier 31 a.k.a. Andromeda galaxy. The center appears to have a black hole which is 18,000 times the mass of Sun. The mass of this black hole allows it to be called an IMBH. Astronomers have classified G1 as a globular cluster .

Globular cluster : As the name implies , globular clusters are spherical clusters of stars which are tightly packed due to high gravitational force. These clusters form along with their parent galaxy and are one of the oldest members of the galaxy.

This black hole is located about 2.3 million light years away from Earth and its size is nearly equivalent to the diameter of Jupiter.

(ii) M82 X-1 : M82 X-1 was discovered in 1999 by NASA’s Chandra X-ray Observatory via detection of its accretion disk. M82 X-1 was producing copious amount of x-rays due to which scientists detected this black hole. This black hole is located in Messier 82 also known as M82 or Cigar Galaxy, which is about 15 million light years away from Earth. According to scientists , this black hole has a mass of 425 solar masses.

3. Supermassive black holes : They are the biggest type of black holes with their mass ranging from 1 million to sometimes a billion solar masses. Researchers have realized that there is at least one supermassive black hole in central regions of most galaxies. Scientists have estimated that the mass of the supermassive black hole at the center of Milky Way, Sagittarius A* or Sgr A*, is about 40 million solar masses located 25,640 light years away from Earth. In some galaxies, the mass of the supermassive black hole can be more than a few billion times than the Sun. These black holes exist in the universe since it was only 700 million years old.

Birth : Scientists don’t exactly know how these monster black holes are formed. There are suggestions regarding the birth of supermassive black holes and according to one, these black holes form from the collapse of massive clouds of gas during the early stages of the universe. And according to another, these black holes are formed from a cluster of black holes merging into one another, forming a supermassive black hole. These black holes could also form from a smaller black hole continuously merging with the celestial bodies around it, leading it to the center of the galaxy.

Mass required to be classified as a supermassive black hole : More than a million times than the Sun.

Location : Mostly found in the central regions of the galaxy.

Method to detect them : Can be found easily by observing  the central region of a galaxy through a telescope.

Some supermassive black holes are :

(i) Sagittarius A* or Sgr A* : Sagittarius A* or Sgr A* is a supermassive black hole located at the center of the Milky Way. This black hole is 26,000 light years away from Earth and has a mass of more than four million times than that of the Sun. This black hole was discovered on 13 February 1974. This black hole is so heavy that it bends space-time to a point where one minute on its edge will be equal to 700 years on Earth. According to scientists this black hole is becoming more active and is emitting more x-ray than it used to.

(ii) TON 618 : TON 618 is the largest black hole ever found. This supermassive black hole was found in 1970 and is 10 billion light years away from Earth. This black hole’s mass is 66 billion times than the Sun. Diameter of this black hole is 390 billion kilometres which is 40 times than the distance from Sun to Neptune. The parent galaxy itself is not visible from Earth because quasar is more luminous than the galaxy itself. It is estimated to be as luminous as 140 trillion Suns.