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 man
