
What is a star?
Stars are big balls of hot gas that changes its luminosity over a period of time. From Earth they are seen very small but actually they are huge. Stars are born in a giant cloud of dust and gas, they also change...sometimes they might shrink due to gravity , lower their luminosity and even explote.

Types of Stars
There are four type of starts which are White Dwarfs, Main Sequence Giants and Super Giants.
White Dwarfs are stars that already died. These stars are white and dim, meaning they don't have as much magnitude as other stars. They are small stars, their temperature is from 6,000 to 20,000 Kelvin.

Giant stars are red stars. Their temperature is from 3,000 to 7,000 Kelvin. Their luminosity is greater than 100 to 10,000.
Super Giants Stars are also red stars. They are huge stars of course. Their temperature is less than 10,000. Their magnitude is greater than 10,000.


This is a diagram that the scientists use in order to classify the stars.
Nuclear Fusion