Question: How did stars develop?★

Rosie Cane answered on 19 Jun 2017:

Good question! First of all, we need to understand that stars have a ‘life cycle’ just like living things here on Earth. And to kick-start this cycle we need to find two really exciting things in space… gas and dust!! Ok, maybe that doesn’t sound too exciting, but gas and dust in space are actually responsible for developing stars, and planets too! They come into the first stage in the life cycle of a star, as a big cloud of gas and dust called a ‘nebula’. This is where stars are born.

This cloud will begin to shrink inwards and as it does, it breaks apart into smaller clumps. These clumps heat up by burning the gas hydrogen, into helium in a process called ‘nuclear fusion’. When their temperature reaches about 10 million degrees celsius, these clumps become new stars.

But that’s not the end of this cycle! These stars then reach a stage called the ‘main sequence’ which they stay at for most of their life-time. Our own Sun is a main-sequence star!

From here, the fate of the star depends on it’s size. Smaller stars will become stars called ‘Red Giants’ that are beginning to cool down. They then become White Dwarf stars and end their life-cycle by fizzling out to become Black Dwarf stars in a fairly boring, un-explosive death.

Then we get onto the exciting, bigger stars that become ‘Red Super-Giants’. Although these stars are bigger, they actually end up living shorter life times than smaller stars as they burn through all of their energy much quicker. They quickly end up as a Supernova (a HUGE explosion) and from there can become either a Neutron Star or a Black Hole.

These explosions in space from the death of a star leave behind clouds of gas and dust, which then can form new stars and start the life-cycle all over again!