Moon and Antares

StarDate: March 3, 2013

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Although it looks like a single reddish-orange point of light, the heart of the scorpion actually consists of two stars. Both of them are far bigger and heavier than the Sun, putting both on the list of the galaxy’s most impressive stars. Yet the two stars will experience far different fates. One will explode, while the other will fade more gently into the night.

The stars form the system known as Antares. It stands close below the Moon at first light tomorrow.

Only one of its stars is bright enough to see with the unaided eye - a red supergiant that’s about 15 times as massive as the Sun.

This star is already nearing the end of its life. Sometime in the next million years or so, it’ll explode as a supernova, briefly outshining entire galaxies of stars.

When the fireworks end, only the star’s dead core will remain - a neutron star. Although it’ll be two or three times as massive as the Sun, gravity will crush it so violently that it’ll be only a few miles across.

Antares’s other star, which is only about half as heavy, should survive the supernova blast just fine, then live millions of years longer. At the end of its life, its outer layers will blow off into space as well, but in a much gentler process. Gravity will crush its now-dead core, forming not a neutron star, but a white dwarf - a ball as massive as the Sun, but about the size of Earth. It’s the same fate that awaits the Sun - in the far-distant future.

 

Script by Damond Benningfield, Copyright 2013

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