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Scorpion’s Tail

July 13, 2017

A scorpion’s most fearsome feature isn’t its claws, although those are pretty scary-looking. Instead, its the stinger — the part that injects venom. And the celestial scorpion has a good one: two stars at the end of its curving tail.

Scorpius is low in the south as darkness falls. The stinger is well to the lower left of Antares, the scorpion’s bright orange heart. It consists of two stars that are side by side, with the one on the left a bit brighter than the one at the stinger’s tip.

Both stars are almost 600 light-years away. The fact that they’re visible to the unaided eye from that distance means they’re extremely bright — among the brightest stars in the galaxy.

The brighter star is Lambda Scorpii. It consists of three stars. Two of them are Class “B” stars — among the hottest and brightest in the galaxy. And at least one of them is destined to explode as a supernova.

The third member of the system is so young that it’s not yet shining as a true star. Instead, it’s a protostar — an object that’s still collapsing to become a star. It should ignite the fires of nuclear fusion before long, joining its older siblings as full-fledged stars.

The stinger’s fainter star is Upsilon Scorpii. It’s a single star. And like the main members of Lambda Scorpii, it’s class B, so it shines many thousands of times brighter than the Sun. It, too, is fated to explode as a supernova — briefly adding to the fearsomeness of the scorpion’s stinger.


Script by Damond Benningfield

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