Potentially lethal gamma-ray burst from star WR 104 could reach earth

Earth may lie in the path of a dangerous gamma-ray burst that could wipe out a quarter of our atmospheric ozone.

Astronomers say WR 104, a Wolf-Rayet star about 8,000 light years away, could go supernova any day, which would generate gamma-rays that could reach earth.

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"We could see it go supernova anywhere from tomorrow to 500,000 years from now," astronomer Grant Hill told Forbes. "For all intents and purposes, the gamma-ray burst and optical photons from the supernova would arrive simultaneously."

Gamma-ray bursts are triggered by supernovae, or exploding stars.

There has been much debate over whether a gamma-ray burst from WR 104 would reach earth, but Dr Hill said it depended on the star's rotation.

"If you look at WR 104 and the image of its pinwheel, it really is a visceral and powerful argument that the thing is face on with an inclination of zero," Dr Hill said. This would mean earth was directly in the line of fire from the star.

University of Kansas physicist Adrian Melott told Forbes such a gamma-ray burst would cause a 50 percent increase in UVB radiation.

"You would first notice a 10-second blue flash in the upper atmosphere, but then the damage would be done," he said.

WR 104 was discovered by University of Sydney astronomer Peter Tuthill in 1998.

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