More Crab Nebula
In the movies, when a star explodes as a supernova, it spreads out evenly in all directions, so it looks like an expanding ball. And for a long time, that pretty well reflected how astronomers thought supernovae really worked.
Today, though, their concepts are changing. Recent research suggests that a supernova may look more like it was blasted out of the ends of an open barrel. In this scenario, material blasts away from the dying star's poles a lot faster than from its equator.
One bit of evidence to support this idea is the Crab Nebula -- the remnant of a thousand-year-old supernova. It's in the constellation Taurus, which is well up in the east by mid evening.
The Crab formed when a massive star exploded, blasting its outer layers into space. The material in the outer layers forms the nebula. After the explosion, only the star's crushed core remained -- a neutron star. It's heavier than the Sun, but only about as big as a city. The neutron star spins about 30 times a second, and it produces a magnetic field that's a trillion times stronger than Earth's.
Photographs show that the Crab is spread out and twisted, and not shaped like a ball. That suggests that it didn't explode evenly in all directions. And "jets" of charged particles shoot into space from the neutron star.
All of this suggests that the jets and the magnetic field helped power the explosion -- an explosion that created a Crab in the night sky.
Script by Damond Benningfield, Copyright 2005
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