Answer :
1. Stars shine brightly, including our Sun, due to the process of nuclear fusion happening in their cores. Nuclear fusion is the process where hydrogen atoms combine to form helium, releasing a tremendous amount of energy in the form of light and heat. This continuous fusion process is what powers the star and makes it shine.
2. Stars appear to twinkle from our perspective on Earth due to the turbulence in the Earth's atmosphere. When starlight enters the Earth's atmosphere, it passes through layers of varying density and temperature, causing the light to refract and flicker. This atmospheric distortion is what creates the twinkling effect that we see when we look at stars at night.
3. Stars are born in massive clouds of gas and dust called nebulae. These nebulae are located in interstellar space. The formation of a young star is triggered when a region within the nebula becomes dense enough that gravity begins to collapse it in on itself. As the cloud collapses, it heats up and forms a protostar. The protostar continues to accrete more gas and dust from the surrounding cloud, eventually reaching a point where nuclear fusion ignites in its core, marking the birth of a new star.
