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Neutron Stars

February 20, 2017

Orion, perhaps the most beautiful of all constellations, stands high in the south as night falls. It’s outlined by a rectangle of four bright stars, with a short diagonal line of three stars at its middle.

Within a few million years, though, all seven of those stars will disappear. Each star will explode, leaving behind a corpse that’s one of the most extreme objects in the universe: a neutron star.

A neutron star forms when a massive star can no longer produce energy in its core. Without radiation to counteract the pull of gravity, the core collapses to the size of a city, even though it’s a couple of times as massive as the Sun. Under that crushing gravitational grip, electrons and protons smash together to form a sea of neutrons, which give these odd stars their names.

The layers of gas around the core fall inward, then rebound, creating a titanic blast known as a supernova.

As the neutron star collapses, it spins much faster, like an ice skater pulling in her arms — up to hundreds of revolutions every second. As it spins, it emits a beam of energy into space. If we happen to line up along that beam, we see the star pulse on and off like a celestial lighthouse, making it a pulsar.

A neutron star may have a crust made of solid iron. But astronomers are still trying to model how neutron stars are put together and how matter deep inside their hearts behaves. A new space telescope will help with that effort. More about that tomorrow.


Script by Damond Benningfield


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