Black Holes are some of the most peculiar and captivating entities in the galaxy. They are incredibly compact, possessing such an intense gravitational pull that even light cannot flee their clutches.

Although spotting these voracious monsters is extremely challenging, the Milky Way may harbour more than 100 million dark stars. At the core of our galaxy resides a supermassive dark star known as Sagittarius . This gargantuan structure weighs approximately 4 million times more than the sun and is located roughly 26,000 light-years away from our planet, as per NASA's announcement. 

What is Black Hole?  

A black hole is a place in space where the gravity is so strong that not even light can escape. Gravity is strong because matter is squeezed into a small space. This can happen when a star dies.

Since there is no light, humans cannot see black holes. you are invisible. Space telescopes with special tools can help find black holes. Special tools can see how stars very close to a black hole behave differently than other stars.

The idea that there are objects in the universe so huge and dense that light cannot escape has been around for centuries. The best known are black holes, predicted by Einstein's general theory of relativity, which show that when a massive star dies, it leaves behind a small, dense residual core. When the core mass exceeds about three times the mass of the Sun, gravity overwhelms all other forces, creating a black hole, as the equation indicated.  

How Black Hole Formed?

Most black holes are created when a massive star undergoes a supernova explosion, leaving behind remnants. Smaller stars end up as neutron stars, which cannot hold light due to their lower mass. If the star's total mass is large enough, around three times that of the Sun, it is theoretically impossible for any force to prevent it from collapsing due to gravity. However, as the star collapses a peculiar phenomenon occurs. As the star's surface approaches the "event horizon," an imaginary boundary, time on the star slows down compared to that of distant observers. Eventually, when the surface reaches the event horizon, time stops, and the star's collapse halts - it becomes a frozen object collapsing in on itself. 

Even larger black holes can be created by stellar collisions. Shortly after launch in December 2004, NASA's Swift telescope observed an intense and fleeting burst of light known as a gamma-ray burst. Chandra and NASA's Hubble Space Telescope later collected data from the "afterglow" of this event, and these observations combined, astronomers believed that a black hole collided with a neutron star, creating another black hole , concluding that a powerful explosion could occur. 

How Big Are Black Holes?  

Black holes  have the potential to vary in size. Researchers consider the smallest dark voids to be as minute as a single atom. These dark voids are incredibly minuscule, but possess the mass of a substantial mountain. Mass is the quantity of matter, or "substance," within an entity.

An alternative type of dark void is referred to as "stellar." Its mass can be up to twenty times greater than the mass of the sun. There could be an abundance of stellar-mass dark voids in the Milky Way galaxy which is the galaxy that Earth is situated in.

The biggest dark voids are identified as "supermassive." These dark voids possess masses that are more than 1 million suns combined. Researchers have verified that each substantial galaxy has a supermassive dark void at its core. The supermassive dark void at the centre of the Milky Way galaxy is named Sagittarius A. It has a mass equivalent to approximately 4 million suns and could fit inside a colossal sphere that could accommodate a  million of Earth. 

Types Of Black Hole

So far  astronomers have identified the three types of black hole which have been searched or found by many scientists and even according to the data of NASA these black holes can be dangerous too. 

• Stellar Black Hole

When a celestial body exhausts all its fuel, it may explode or collapse. If the star is smaller (weighing up to three times that of the sun), it results in a white dwarf or a neutron star. However, if the star is bigger, it continues to compress and gives rise to a stellar black hole 

Though relatively small, black holes that emerge from the collapse of individual stars are incredibly dense. Such an object can hold more than three times the mass of the sun within the confines of a city's diameter. This creates an immense gravitational pull on surrounding entities. Stellar black holes gradually ingest the gas and dust from their neighbouring galaxies, which causes them to expand. 

• Supermassive Black Hole

The universe is filled with small black holes, but their relatives supermassive black holes are the ones in charge. These massive black holes are millions or even billions of times the mass of the sun but have about the same diameter. It is thought that these black holes are located at the centre of almost every galaxy, including the Milky Way.

Scientists do not know how these large black holes form, but they do gather mass from the abundant dust and gas in the centre of galaxies, allowing them to grow even larger. Supermassive black holes may be created by combining hundreds or thousands of small black holes. Large gas clouds could also be responsible, as they collapse and quickly accumulate mass. A third possibility is the collapse of a group of stars, known as a stellar cluster, falling together. Fourth, supermassive black holes could arise from large clusters of dark matter. Although we can observe dark matter through its gravitational effect on other objects, we do not know what it is made of because it does not emit light and cannot be directly observed.

• Intermediate Black Hole

In the past, scientists believed that black holes only existed in small or large sizes. However, recent research has suggested the possibility of intermediate or mid-sized black holes (IMBHs). These IMBHs could be created when stars in a cluster collide in a chain reaction. If multiple IMBHs form in the same area, they could eventually merge and create a supermassive black hole at the centre of a galaxy.

In 2014, astronomers discovered what seemed to be an IMBH in the spiral arm of a galaxy. Additionally, in 2021, astronomers detected one by taking advantage of an ancient gamma-ray burst.

Tim Roberts, a co-author of the study from the University of Durham in the United Kingdom, stated that "Astronomers have been diligently searching for these medium-sized black holes. Although there have been indications of their existence, IMBHs have been elusive like a long-lost family member who doesn't want to be found. 

Conclusion Or Could A Black Hole Destroy The Planets

Black holes are invisible because their strong gravitational pull pulls all light to the centre of the black hole. But scientists can see how the strong gravitational force affects the stars and gas around the black hole. Scientists can study stars to see if they fly around or orbit black holes. High-energy light is emitted when a black hole and a star come close. This type of light cannot be seen by the human eye. Scientists use satellites and telescopes in space to see high-energy light.  

Absence of openings do not drift in the cosmos devouring celestial bodies such as stars, moons, and planets. The planet Earth cannot be captured by a black hole since no black hole exists in the vicinity of the solar system to accomplish that.

Even if a black hole with identical mass to that of the sun were to replace it, Earth would still not be absorbed. The gravitational force exerted by the black hole would be equivalent to that of the sun. Therefore, Earth and the other planets would continue to revolve around the black hole, just as they orbit the sun at present. The sun will never transform into a black hole since it is not a massive enough star to generate one.