Why Do Stars Shine Brightly?

Stars shine because they are giant balls of gas that are squeezing themselves very hard. Imagine holding your hands together tight and rubbing them fast. Your hands get warm. Stars do this on a huge scale.

Inside a star, gravity pulls everything to the middle. This makes the center very hot and squished tight.

When atoms are squished hard enough, they smash together. This is called nuclear fusion. Two tiny hydrogen atoms join to make one helium atom. This smash releases a tiny bit of energy as light and heat.

This energy travels from the center to the outside. It makes the star glow bright yellow or white. So stars shine because they are constantly smashing atoms together in their hot centers. It is not fire like a campfire. It is a nuclear party inside the star.