Magnetars

StarDate: March 5, 2009

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Thirty years ago today, a wave of energy swept through the solar system. It was unlike anything that astronomers had ever seen before -- and it took years to explain it. And even today, the explanation sounds like something from science fiction: a crack in the crust of a dead star.

The saga began on the morning of March 5th, 1979. Ten spacecraft scattered around the solar system recorded an outburst of X-rays and gamma-rays. The outburst was so strong that the spacecraft couldn't accurately measure it.

Because it was so strong, astronomers thought the outburst must have been fairly close by; a long-distance burst would have required an almost inconceivable amount of energy.

Over the next few years, though, they recorded several more outbursts from the same position in the sky. That allowed them to track down the source: the Large Magellanic Cloud, a galaxy that's about 170,000 light-years away.

In fact, the outbursts came from inside a cloud of hot gas -- the remains of an exploded star. That suggested that the source of the outbursts was the star's crushed core, called a neutron star -- a ball that's several times as massive as the Sun, but no bigger than a city.

Not until years later did astronomers find an explanation: An extremely powerful magnetic field was ripping apart the neutron star's crust, creating a "fireball" of energy. Such a highly magnetic star needed a new name, and it got one: magnetar.

More about magnetars tomorrow.

Script by Damond Benningfield, Copyright 2009

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