Did You Know: Space – What happens when stars die?
Just like everything else in our universe, stars are born and eventually die.
Some stars have very quiet deaths, and others end with massive explosions.
Follow this diagram to see how different stars change throughout their lives.
Average star
An average star is a star like our sun. This kind of star stays the same size and shape for about 10 billion years before it begins to die.
Red giant
As an average star nears the end of its life, it slowly begins to get bigger and cooler. It is then known as a red giant.
Stellar nursery
A stellar nursery is a cloud of very hot gas. This is where new stars are born.
Stars are made from gas and dust. Stars with more gas and dust will be larger.
Massive star
Massive stars are formed in the same way as average stars. However, they are much bigger and use up energy faster, so they don’t live as long.
Red supergiant
This is the largest type of star in the universe. Red supergiants are massive stars that have become bigger and cooler toward the end of their life.
Planetary nebula
As the star starts to run out of fuel, its core, or center, collapses and it loses its outer layers. It is now known as a planetary nebula.
White dwarf
The leftover core of the star is called a white dwarf. This will eventually cool to become a black dwarf.
Neutron star
These are tightly packed, tiny stars. They measure no more than 10 miles (16 km) across.
Supernova
At the end of the red supergiant’s life, there is a massive explosion called a supernova. This throws the outer layers of the star out into space. The core of the star may become a neutron star or a black hole.
A black hole forms when the core of a dying star becomes so tightly packed into a tiny space that nothing can escape— not even light.
When did we last see a supernova in the Milky Way?
Kepler’s Supernova
The last time we saw a supernova in our galaxy was just over 400 years ago. The explosion, now called Kepler’s Supernova, was brighter than any other star in the night sky for a few weeks.