Red Giants

Red giants are large, luminous stars that have expanded and cooled after exhausting the hydrogen fuel in their cores. As the core contracts under gravity, it heats up and causes the outer layers to swell outward, creating a bright, reddish appearance. These stars are in a late stage of stellar evolution, usually after spending millions to billions of years fusing hydrogen into helium. Despite their size and brightness, they are not necessarily more massive than the Sun. Red giants eventually shed their outer layers, leaving behind dense cores called white dwarfs, and they play a vital role in enriching the universe with heavier elements.