Let’s start the discussion with something that we know and see daily. We have studied from childhood that stars are the massive bodies in the universe that shine by themselves. We also know the closest star to us, The Sun. But, what is it that makes The Sun and other stars like it shine so brightly for almost forever?
Firstly, let’s address the fact that there are many types of stars. The Sun, is a Main sequence Star. Some stars are bigger than sun viz, Giants and Super Giants. Some stars are smaller than The Sun viz, White dwarfs. Basically, at the time of birth stars are a huge mass of gas. In general, all the stars are made up of two thirds of Hydrogen and one thirds of Helium. These gases form a cloud which collapses when the pressure and temperature are high enough to start a Nuclear Fusion reaction. Thus a Star is born.
The Nuclear Fusion fuses two Hydrogen atoms to a Helium atom generating a massive amount of energy at very high temperatures almost to millions of degrees. This process is continued for the most of the lifespan of the star and these stars are called the Main sequence stars. You might be thinking that fusing two Hydrogen to helium is the cause of the light and the heat of The Sun but, the Hydrogen deposits will be extinct some time or later. Yes. You are right. The Fusion reactions on The sun Gallop Hydrogen at the rate of almost 4 Million Kg per second. But, the mass of The Sun is so huge that even at this rate it will still take Billions of years for the Hydrogen deposits to become extinct. Continue reading