1. THE LIFE CYCLE OF STARS
Chapter
15-2
Part 3

2. The Aging of Massive Stars
Massive stars use their hydrogen much faster than stars like the sun do.
Since these stars generate more energy, they are very hot, but also have shorter lives.
They also have very dramatic ends!

3. Supernovas
A supernova is a gigantic explosion in which a massive star collapses and its outer layers are blasted into space.
Even larger stars can become neutron stars, pulsars, and black holes.

4. Neutron Stars
Following a supernova, the center becomes a very dense and small ball of neutrons.
This is called a neutron star.
A single teaspoon of this weighs 100 million metric tons on Earth.
A neutron star 20x smaller than our sun would emit the same energy as 100,000 suns.

5. Pulsars A pulsar is a swiftly rotating neutron star.
It can only be detected on Earth when their beams of radiation sweep past the Earth.

6. Black Holes
Sometimes leftovers of supernovas are so massive that they collapse to form a black hole.
A black hole is so small and massive, and its gravity is so strong that not even light can escape its pull.
That’s why it’s called a black hole.

7. THE END