What makes you grow up to be tall or short, or have big or small bones? Your shape depends on the genes you get from your parents. But a star’s life is shaped by only one thing: how massive it is when it is born.
Stars with more mass burn hotter and brighter. They also burn out faster. So stars that keep cool live longer by burning slower. The hottest stars are blue. The coolest stars are red. Others are yellow, like our Sun. Most stars in our galaxy are red dwarfs. Here are some of the different kinds of stars.
