Stars are large, glowing balls of very hot gas. This gas is called plasma.
The Sun is a star. It is the closest star to Earth.
Stars can look small in the sky. This is because they are very far away. In reality, stars are huge. Many are millions of times larger than the Earth.
After the Sun, the nearest star is Proxima Centauri. It is about 4.3 light-years away. This distance is roughly 41 million, million kilometres.
Astronomers study how bright stars appear.
One way to describe this is brightness. Another word often used is luminosity. This means how much light a star gives off.
All stars are formed inside clouds of gas and dust called nebulae. Stars form with different sizes and colours. These features help astronomers identify the type of star.
Stars shine for millions of years. They do not shine forever. Over time, stars change. These changes happen in stages which we call the life cycle of a star.