What is Black Hole?

A black hole is a cosmic body in the center of almost every galaxy in the universe, including the Milky Way galaxy, in which our solar system exists. The gravity and intensity inside the black hole are so strong that it attracts everything coming towards it, even electromagnetic radiation cannot escape. Hence, a black hole cannot be observed directly. However, it can be observed by its gravitational influence on nearby matter. The boundary of black holes is called the ‘event horizon’.

A black hole is a massive object (or region) in space that is so dense that within a certain radius, its gravitational field does not let anything escape from it, not even light. It is thought that giant stars will evolve into red supergiant, ten supernova and then black holes. Typical black holes have a mass of roughly 10 times that of the sun, but the range must be huge. Astronomers think that there may be a black hole at the center of each galaxy.

Black holes form from massive stars that collapse under their own gravity.

Some examples of black holes are:

• CygnusX-1
• Sagittarius-A

Discovery of Black Hole

 The term “black hole” was coined many years later in 1967 by American astronomer John Wheeler. After decades of black hole being known only as theoretical objects.The first black hole ever discovered was Cygnus X-1, located within the Milky Way in the constellation of Cygnus, the Swan. Astronomers saw the first signs of a black hole in 1964 when a sounding rocket detected celestial sources of X-rays according to NASA.  In 1971, astronomers determined that the X-rays were coming from a bright blue star orbiting a strange dark object. It was suggested that the detected X-rays were a result of stellar material being stripped away from the bright star and “gobbled” up by the dark object an all-consuming black hole.

Formation of Black Hole

 Black holes form is from the direct collapse of gas, a process that is expected to result in more massive black holes with a mass ranging from 1000 times the mass of the sun up to even 100,000 times the mass of the sun. This channel circumvents the formation of the traditional star, and is believed to operate in the early universe and produce more massive black hole seeds.

A black hole is formed by the death or explosion of extremely massive stars with sizes of more than three solar masses. At the end of the massive star’s life, the core of the stars become highly unstable and collapses. The crushing weight of its constituent matter falling in from all sides compresses the dying star to the point of zero volume and infinite density called the singularity.