A Star Is a Big Ball of Gas
A brownish cloud of glowing gas in a star-filled area of space

Stars are born in a nebula like this one. Image Credit: NASA

Twinkle, twinkle, little star.
How I wonder what you are.

What is a star?

A star is a big ball of gas. It is not star-shaped. Stars give off heat and light.

How is a star made?

Stars are born in nebulas. Nebulas are clouds found in space. They are made of gases and dust.

A star's color tells us how hot or cold it is. The bluish stars are the hottest ones. The reddish stars are the coolest. But they are still very hot!

A thermometer showing that blue stars are the hottest, red stars are the coolest and white, yellow and orange stars are in between

Red stars are not as hot as blue stars. Image Credit: NASA

Our sun is a yellow star. That makes it one of the cooler stars.

The sun looks very big to us. But it is just a medium-sized star. The sun looks so big because it is close to the Earth.

Twinkle, twinkle, little star.
Now I know just what you are.