Why Stars Shine ?

Stars shine due to nuclear fusion happening in their cores. This process involves the conversion of hydrogen into helium under extreme temperature and pressure conditions. In the core of a star, hydrogen atoms are forced together by the immense gravitational pressure. When the temperature reaches millions of degrees Celsius, hydrogen atoms collide with each other with enough force to overcome their natural repulsion (due to their positive charges) and merge, forming helium atoms.

This fusion process releases an enormous amount of energy in the form of light and heat. The light generated from this nuclear fusion process is what we perceive as the star’s brightness. This energy radiates outwards, providing the light and heat that sustains the star’s luminosity and allows it to shine. This continuous process of nuclear fusion is what powers stars, including our Sun, and enables them to emit light and heat over billions of years.