Stars really do die! Even though they seem like eternal lights in the sky, stars go through a full life cycle, from birth to death, just like living things. How a star dies depends on how big it is.
Stars are born in huge clouds of gas and dust floating in space. Over time, gravity pulls the material together to form a star. Once it gets hot enough inside, the star begins fusing hydrogen into helium, creating energy that makes it shine. This process can last for millions to billions of years.
But stars don’t shine forever. Eventually, they run out of fuel. When that happens, the balance between gravity pulling in and pressure pushing out is lost. The star starts to collapse under its own weight.
Smaller stars, like our Sun, swell into red giants and shed their outer layers, creating beautiful glowing clouds called planetary nebulae. What’s left behind is a white dwarf—a hot, dense core that slowly cools and fades over billions of years.
Bigger stars go out with a bang—literally. When they collapse, the core falls in so fast that it causes a massive explosion called a supernova. These explosions are powerful enough to outshine entire galaxies for a short time! The remains of the core may become a neutron star or, if the star is huge enough, a black hole—a mysterious object with gravity so strong that not even light can escape.
Dying stars also give back. They scatter elements like carbon, oxygen, and iron into space—ingredients that form new stars, planets, and even life. So, a star’s death helps the universe begin new stories.
