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December 1, 2011

There aren’t enough superlatives in the English language to do justice to Betelgeuse, the bright orange star that marks the shoulder of Orion, the hunter. Its diameter is at least 300 times that of the Sun, and perhaps much more. It puts out about a hundred thousand times more energy than the Sun does. And when it dies, it will create a fireball that will briefly outshine billions of normal stars.

Betelgeuse is a red supergiant — the largest class of stars. It’s probably close to 20 times as massive as the Sun. The gravity of such a star squeezes its core tightly, heating it to billions of degrees.

Such a stellar blast furnace consumes its original hydrogen fuel in a hurry, “fusing” the atoms together to make helium and producing incredible amounts of energy in the process.

It then fuses the helium to make heavier elements — carbon and oxygen at first, and eventually all the way up to iron. When that happens, the star no longer produces energy in the core. Without the reactions in its core to push outward, gravity quickly causes the core to collapse, forming a neutron star. A massive explosion rips through the star’s outer layers, blasting them into space at a few percent of the speed of light — a titanic blast known as a supernova.

We can’t be sure when that will happen to Betelgeuse, but it’s probably pretty soon — just about anytime in the next hundred thousand years.

We’ll have more about Betelgeuse tomorrow.


Script by Damond Benningfield, Copyright 2011


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