Pre-main-sequence star

Stars are born in giant clouds of gas and dust. When a star is just starting out, it's called a pre-main-sequence star. It's like a baby star that hasn't learned to shine its brightest yet. It's still growing by gobbling up more gas and dust from around it. This is a super important time for a star!

A pre-main-sequence star gets bigger by pulling in stuff from a cloud around it. Once it has almost all the stuff it needs, it starts to shrink. As it shrinks, it gets hotter and hotter inside. It's like squeezing a balloon – it gets warmer! This shrinking is what makes it a pre-main-sequence star.

This star baby is getting ready for its big moment! It's still shrinking and getting hotter inside. Soon, the middle of the star will get so hot and squeezed that it will start to make its own light and heat, like a giant furnace. That's when it becomes a grown-up star, ready to shine for billions of years!

Some baby stars are smaller, like our Sun. They take a long time to get ready. Bigger, super-giant baby stars get ready much faster! They are so big and hot that they skip some of the baby steps and become grown-up stars very quickly.