Briefly explain the formation of stars? And what must happen before a nuclear fusion starts?
Stars form from vast interstellar clouds of gas and dust known as nebulae. These nebulae are primarily made up of hydrogen and helium, the two lightest elements in the periodic table.
To start the formation of a star, the gas and dust in a nebula must be compressed and heated. This can happen through a variety of ways, such as the shock wave of a nearby supernova explosion or the gravitational collapse of a dense region within the nebula.
Once the gas and dust are compressed enough, the core temperature of the forming star becomes hot enough to initiate nuclear fusion. This process involves the fusion of hydrogen atoms to form helium, releasing a tremendous amount of energy in the form of light and heat. The intense radiation pressure generated by this fusion process counteracts the force of gravity trying to collapse the star further, resulting in a stable and long-lasting star.