Neutron star (noun, “NEW-tron star”)
This is the leftover corpse of a large star after it has exploded. When a very large star (one that’s four to eight times as big as our sun) dies, it explodes into a supernova. The massive blast shoots most of the mass from the star into space, making that star shine brightly for a brief time. A truly massive star that goes supernova will collapse inward to form a black hole. But what if the star isn’t quite massive enough for that? The center of the former star collapses inward from the force of its own gravity. Inside this super-dense core, the dead star lives on. Negatively charged particles called electrons and positively charged particles called protons fuse into neutral particles called neutrons. These neutrons are why this zombie star is called a neutron star.
Neutron stars are dense. Really, really dense. They are so dense that single teaspoonful of neutron star material would weigh a billion tons on Earth. That’s as much as 166 Great Pyramids of Giza!
In a sentence
When two neutron stars smack into each other, they produce gold, silver — and gravitational waves.
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