Sol – Our Sun

Our Sun – The Sol is the star placed at the centre of our Solar System. It is a sphere of hot plasma. It is a G-type main-sequence star (G2V) based on its spectral class. It is informally referred to as yellow dwarf star which is not entirely correct.

It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud of Hydrogen. Most of the hydrogen gathered in the centre, whereas the rest flattened into an orbiting disk that became the Solar System. The mass of the matter crushed the sphere towards the centre where the higher temperature and pressure crushed the hydrogen at the centre to initiate nuclear fusion. The gravitational push towards the centre and the higher temperature and pressure at the centre creates hydrostatic equilibrium. Once the hydrogen is fused in to helium the hydrostatic equilibrium will no longer stay in place creating a misbalance. Eventually the star will explode into planetary nebula and the centre of the star will reduce to a white dwarf.

The Sun still has a life span of about 5 billion years during which it can nurture Earth and its life forms like it has been doing for millions of years in the past. The Energy from Sun in the form of heat and light has supported the conditions on Earth to sustain life and eventually every species on Earth (except a rare few) depends on Sun directly or indirectly depends on Sun for its survival.

The energy from Sun allows the plants to make their own food, allow herbivorous animals and humans to gain energy and hence allow carnivorous animals to survive on as well. The heat from the Sun is just enough to ensure safe ambient temperatures across the planet. The water cycle is also responsible due to heat of Sun experienced by Earth.