Moon and Antares

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If stars experienced the same sibling rivalry as people, then the "œlittle brother" of the Antares system would have quite a complex.

The star is known as Antares B. On its own, it would be quite impressive. It's perhaps seven or eight times as massive as the Sun, and its surface is many thousands of degrees hotter, so it shines blue-white. It's quite bright, too.

Yet it pales when compared to its big brother, Antares A -- one of the biggest, brightest, and heaviest stars in the galaxy.

Antares A is classified as a supergiant. It's about twice as massive as Antares B, much larger, and close to a hundred times brighter. In fact, it's one of the handful of brightest stars in our night sky, even though it's about 600 light-years away. By comparison, if you could pick out Antares B through the glare of its brighter sibling, it would barely be bright enough to see with the eye alone.

Antares A will die a more spectacular death than its little brother, too. Within the next few million years, it's likely to blast itself to bits as a supernova.

The explosion probably won't damage Antares B. Instead, the star will get one benefit from its less-flashy existence: Because it's less massive, it will outlast its sibling by many millions of years.

Look for Antares -- reddish-orange Antares A, that is -- rising just above the Moon late this evening. You'll need a good telescope and steady skies to pick out the weaker glow of Antares B.

Script by Damond Benningfield, Copyright 2008

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