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The Stinger

July 19, 2015

The celestial scorpion has a potent stinger — a pair of bright stars at the tip of its curving body. They’re low above the southern horizon as night falls, with the rest of Scorpius curling to their upper right.

The brighter star in the stinger is known as Lambda Scorpii. It’s the second-brightest star in Scorpius, so it’s hard to miss. Fainter Upsilon Scorpii stands close to its right.

Lambda actually consists of three stars. The system’s main star is more than 10 times as massive as the Sun. At that great heft, it consumes its nuclear fuel in a hurry. It’ll soon begin to exhaust its fuel, so it’ll puff outward. The star will engulf its nearer companion, which is only a few million miles away. That’ll probably destroy the companion, perhaps sending its core spiraling into the core of the main star. That may hasten the demise of the bigger star, which is likely to explode as a supernova.

Upsilon is a single star, but it’s also a stunner. It’s about 10 times the Sun’s mass, and it’s many thousands of times brighter.

Although Lambda and Upsilon appear quite close together, they’re more than 150 light-years apart. Even so, the stars are related. They were born from the same giant complex of gas and dust. This region has given birth to many massive stars, including Antares, the scorpion’s bright orange heart. But the stars are only loosely bound together, so they’re moving apart — spreading their magnificence across the galaxy.

Script by Damond Benningfield, Copyright 2015

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