What Are Stars Made Of?

Stars are giant balls of hot gas that shine because they're burning inside like a fire.

Imagine you have a big balloon full of air, but instead of air, it's filled with something called hydrogen, which is the most common element in the universe, kind of like how oxygen is what we breathe every day. When stars are born, this hydrogen starts to burn in a process that scientists call nuclear fusion, turning into another gas called helium. This burning makes them super hot and bright.

If you could look inside a star, it would be like stepping into the middle of a huge, glowing kitchen, except instead of food, there’s a lot of hydrogen and helium, and sometimes even other elements like carbon, oxygen, or iron. These extra ingredients are created when the burning inside gets really intense.

Stars shine because they're constantly burning this hydrogen into helium, which releases energy in the form of light and heat, kind of like how a campfire glows because it’s turning wood into ash and smoke.