Every star has a finite fuel with which it burns the gases present inside it and gives off luminosity as the energy obtained from the reactions. However, a star more massive than the sun will not always have the same fate as the sun. They all go on different paths in their life based on their mass characterization.

The two end states of the star much more massive than the sun are Neutron Stars and Black Holes.

(1)   Neutron Stars

Neutron Stars are very compact and dense objects made up of only neutrons. They are formed when the stars of 1.5 times the solar mass reach the end stage of their life and give rise to supernovae explosions. But the gravitational pull is so strong that by the reverse beta decay process, the electrons and protons are converted into neutrons. These stars get balanced at the point when the neutron degeneracy pressure balances the intense gravitational pull. These stars have intense gravitational pull of orders that Mount Everest would compress to the size of a teaspoon. They also have higher orders of intense gravitational pull.

Magnetars (a class of Neutron stars) have been observed to consist of magnetic fields which are strong enough to split away the electrons in a human body situated near the vicinity of one. They give off huge magnetic streams when star observes a “starquake” and releases huge streams of charged particles.

(2)   Black holes

Black Holes or say vacuum cleaners of the cosmos are the one of the most dangerous and violent places known to humans in the known Universe. They are formed when stars of the mass 3 times the solar mass reach the end stage of their life and give rise to Supernovae explosions. But the inward gravitational pull is so intense that all the mass of the star gets compressed to a single point. The gravitational pull here is so intense that no even light can escape it. According to the Theory of General Relativity, the curvature of spacetime at the center of the black hole is infinite as it is a point of infinite mass. The intense gravitational pull of the black hole bends spacetime and also slows down the time in the near vicinity of the black hole. So, if an observer were to go towards a black hole, the time in his surroundings will begin to slow down as he gets near the center of the black hole. The current equations in physics don’t allow for a point to have infinite mass. So, our current theory of black holes is incomplete right now and the only way to complete it to reconcile quantum mechanics with general relativity.

There are 3 type of black holes known in nature classified on the basis of their sizes-

(a)   Stellar Mass black holes = These black holes consist of mass 3 to 10 times the mass of the sun and their existence has been proved via sufficient independent observational evidence provided from ground based telescopes and space based telescopes.

(b)   Intermediate Mass black holes =These black holes consist of 100 to 1000 times the mass of the sun and not much evidence exists as to the confirmation of these bodies.

(c)   Supermassive Black Holes = These black holes consist of a mass of the order millions to billions of solar masses and have been hypothesized to have been found at the center of every galaxy where it assists in the formation and regulation of galaxies.


A Brief History Of Time: From Big Bang To Black Holes

Black Holes And Baby Universes And Other Essays

Written by-

Sukhjit Singh, He is a student currently pursuing B.Sc. Mathematics honors from SGTB Khalsa College, Delhi University. He aims at developing multiple skills by taking up exciting projects and wants to a professor in Mathematics.

Edited by-

Shweta, Team SciComm