Plaskett's Star

StarDate: February 21, 2009

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Brilliant Orion stands proudly in the south this evening. A big rectangle of bright stars outlines his body, while a short line of three stars in the middle represents his belt.

Two supergiants stand at opposite corners of the rectangle: orange Betelgeuse at the upper left, and blue-white Rigel at the lower right. Both stars are much bigger and more massive than the Sun. Yet a pair of stars in a neighboring constellation dwarfs both of them.

Monoceros, the unicorn, is to the left of Orion. To the eye alone, it's a bust. But the constellation includes one of the most impressive binary star systems in the galaxy. It's called Plaskett's Star, after the astronomer who discovered it.

This remarkable system consists of two supergiants, both of which are more impressive than Orion's luminaries.

One of the stars is more than 40 times as massive as the Sun, while the other is more than 50 times as massive. Both stars are also much bigger and hotter than the Sun. Most impressive of all, they're hundreds of thousands of times brighter than the Sun. But they're thousands of light-years away, and they're partially veiled by clouds of dust, so they don't look impressive to the unaided eye.

That won't always be the case, though. Each star will end its life as a supernova -- a titanic blast that will rip the star apart. For a while, the stars will outshine everything else in the night sky except the Moon -- briefly stealing Orion's glory.

Script by Damond Benningfield, Copyright 2008

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