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article imageThe 'Death Star' threatens Earth, sort of

By Paul Wallis     Mar 11, 2008 in Science
It looks fetal in the picture, but this actually two stars tearing each other to pieces. They orbit each other every eight months. One of them’s a star called a Wolf-Rayet star.They tend to explode from the poles, and Earth is directly overhead.
The Solar System isn’t on the galactic plane. It’s above it. Because we’re part of an old galaxy (The Sagittarius cluster) that was absorbed by the Milky Way, we’re also moving around the galaxy in the opposite direction to most of the rest of the galaxy.
Which is why we have a raging Wolf-Rayet star underneath us. This thing is generating huge clouds of gas, which gravity is turning into a spiral.
It’s quite a spectacular sight, but even that’s not the problem.
The problem is that it might become a supernova. Supernovae are fun. One of them may well have set off an explosion which blew up half a galaxy, just recently. They’re not dull.
If so, not only will it produce the stellar equivalent of a hydrogen bomb explosion, it will also produce gamma rays.
Gamma rays are huge, powerful surges of energy which are believed to travel faster than light, and according to many people they could wipe out life on Earth.
The Sydney Morning Herald:
"From our vantage point," said Dr Tuthill, (University of Sydney astronomer whose team discovered the star) "we are looking right down the gun barrel. That's what's got us worried."
In 2003 a University Of Kansas astrophysicist, Adrian Melott, said a cosmic gamma ray burst from an exploding star triggered a mass extinction of life 443 million years ago. Dr Tuthill said it was impossible to say when WR 104 would explode. "It could be tomorrow, or in 100,000 years [but] it will definitely blow up. It's a ticking bomb."
Although the star was a possible candidate for a burst of gamma rays, "there are a lot of uncertainties". And more work was needed to establish the exact path of any radiation blast.
So it’s threatening Earth, in a manner of speaking.
Actually our neighborhood has a few other things to think about: Betelgeuse and Antares, supergiant stars, could make the Wolf-Rayet look like a firecracker if they went nova. Betelgeuse is 600 light years away, and the shock wave alone would flatten the sector. Antares is 8.6 light years away. The Wolf-Rayet is 8000 light years away.
The idea of cosmic events destroying life on Earth isn’t new.
Many say that because of them, life couldn’t exist at all, and probably never has.
These people are called marketing consultants.
More about Wolf rayet stars, Gamma rays, Astronomy