Stargazers: See a true winter superstar­­ — Betelgeuse


Many years ago, a friend was taking a basic astronomy course to fulfill her science requirements at a major university. She was doing quite well, in fact. She could cite the distances of all the planets, describe the expansion of the universe, and even explain how stars are born and die.

One evening we were discussing the stages that some stars experience on their way toward death — the red giant and super-giant phases. In the course of our conversation, I mentioned the bright star Betelgeuse in the constellation Orion, perhaps the most famous of all red supergiant, and asked if she had ever seen it.

Her puzzled look and response startled me. "You mean you can actually see a red supergiant star," she skeptically replied.

There she was, filled with all this knowledge of arcane astronomical data, and no one had ever bothered to take her out at night to see one of the greatest and nearest red super-giants known: Betelgeuse.

Betelgeuse shines brightly in the upper left corner of Orion, it represents the shoulder the great hunter, and you can see it glowing brightly low in the southeastern sky after dark. Its unusual name comes from the Arabic term Ibt al-Jauzah meaning "armpit of the Central One," not surprising considering its location within the hunter's outline.

With about 1520 times more mass than our sun, Betelgeuse is one of the first ever to have its size measured. And it's big. Very big. While we could align 109 Earths across the face of our sun, it would require 1,000 suns to cross the face of Betelgeuse.

Indeed, Betelgeuse is so immense that, if we could bring it to our solar system to replace our sun, the star would engulf the orbits of Mercury, Venus, Earth, Mars and Jupiter! Yet, it appears as a point of light in our night sky because of its great distance from us — some 520 light-years or about 3,100 trillion miles.

Betelgeuse remains one of the largest stars known, even though its size fluctuates by as much 60 percent as the star shudders and pulsates.

Astronomers agree that Betelgeuse is nearing the end of its life. It shudders and pulsates, and will soon erupt in a violent supernova explosion. But "soon" is a word that means something different to astronomers than to most people; it may be a few thousand or tens of thousand years from now when Betelgeuse erupts. But when it does, it will surely produce one of the most dramatic celestial displays that stargazers have ever seen from our planet.

Such a supernova would temporarily produce more than a billion times more power than our sun. Sounds terrifying, until we realize that its great distance would weaken its light to about the brightness of Venus.

What an explosive Betelgeuse would do is inspire people to go outside to look up at the heavens, many for the first time in their lives, to see one of nature's great sky shows. And that wouldn't be such a bad thing!

So never mind all this arcane astronomical data — get out under the stars to see this remarkable superstar for yourself!

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