http://www.cosmosmagazine.com/node/1878

SYDNEY: A spectacular, rotating binary star system is a ticking time bomb, ready to throw out a searing beam of high-energy gamma rays – and Earth may be right in the line of fire.

Astronomers at the University of Sydney, in Australia, first discovered the unusual and beguilingly beautiful star system eight years ago in the Constellation Sagittarius. One member of the pair is a highly unstable star known as a Wolf-Rayet, thought to be the final stage of stellar evolution to precede a cataclysmic supernova explosion.

"When it finally explodes as a supernova, it could emit an intense beam of gamma rays coming our way", said Peter Tuthill, lead researcher of the team that report their findings in the current Astrophysical Journal.

Vast and glowing plume

At a distance of 8,000 light-years from Earth, the pair of stars are a short hop away in galactic terms, and just one quarter of the way to the centre of our Milky Way galaxy.

The researchers took images of the system, known as WR 104, over a period of eight years using Hawaii's Keck Telescope. These images reveal a vast and glowing plume of heated dust and gas, billowing out in a spiral as the stars rotate once every eight months. This 'tail' is up to 30 billion kilometres long.

But something curious about the images caught the attention of the experts.

"Viewed from Earth, the rotating tail appears to be laid out on the sky in an almost perfect spiral. It could only appear like that if we are looking nearly exactly down on the axis of the binary system," said Tuthill.

This means we are peering down the barrel of the gun, as when binary supernovae go off, all their energy is focussed into a narrow beam of wildly destructive gamma ray radiation that emanates (both up and down) from the poles of the system.

"If such a gamma-ray burst happens, we really do not want Earth to be in the way," he said. "I used to appreciate this spiral just for its beautiful form, but now I can't help a twinge of feeling that it is uncannily like looking down a rifle barrel."

Sterilising effect

Though the risk may be remote, there is evidence that gamma ray bursts have swept over the planet at various points in Earth's history with a devastating effect on life.

A 2005 study showed that a gamma-ray burst originating within 6,500 light-years of Earth could be enough to strip away the ozone layer and cause a mass extinction. Researchers led by Adrian Melott at the University of Kansas in Lawrence, U.S., suggest that such an event may have been responsible for a mass extinction 443 million years ago, in the late Ordovician period, which wiped out 60 per cent of life and cooled the planet.

Further research would be required to determine if we are exactly in line with the axis of the system – but even if we are, we probably still have hundreds of thousands of years to come up with a solution, said Tuthill.

with the University of Sydney

If we are able to expand our knowledge 100,000 years worth, I do not think we will have a problem. Defeating or preventing a gamma ray burst from hitting the Earth, will probably be a piece of cake.

Should this thing happen to start with the Gamma waves tomorrow, it would be 8,000 years before we feel anything.
There is way to many ifs and maybes...

We know how to stop Gamma waves already.... Should be in such a situation were this is going to happen the main problem we would face is a combination of time and money. (And materials)


**Wow... what a misleading title...***

This post has been edited by Xeno: Mar 13 2008, 04:34 PM

Here we have a biased post. I have a link to this story in my email at work so I can't post it..YET. as I am at home.
But if you read the WHOLE story you will see that the odds are pretty darn slim, at 8000 light years away, the alignment needed to get earth is staggeringly difficult, it would only need to be a poofteenth of nothing off course to miss us. So it is Not impossible, but bloody unlikely. But some reports conveniently leave that bit out. There was many many qualifiers that said it is unlikely. But it sells more papers so to speak to put it in its worse light. Im my opinion, just another case of irresponsible journalism. But you can bet in 5 years time this will be the next doomsday cause. This is exactly how it starts.
Not digging at you cricket , just the article

This post has been edited by Dundee: Mar 14 2008, 02:21 AM

Why does it takes so long for gamma rays to get to us?

Gamma ray travel at the spped of light, if they have to travel 8000 light years, if they leave right now, they will take 8000 years to get here, traveling at the speed of light. But just to throw a spanner in the works, if it has already done the deed, 7999 years 364 days ago, that means we are gonners tommorow.
For example, if our sun blew up, we would not know for 8.32 minuts, because that how long it takes light to get here to earth, from the Sun.

Check this site out, it tells all better then me
http://www.haydenplanetarium.org/universe/..._time_dista.php

Ok I just did a little bit of really quick maths and I am sure if I am wrong It will be very quicky pointed out.

They said it looks like it is aligned with earth, and if the gamma rays come our way we are toast. I wondered how much it would take to miss us???

Well what happens if the alignment was out by only 1 second 1/60th of 1 degree, now that is not much.
It is 8000 light years away, so that is around 9,460,800,000,000 kilometers.
So the center of alignment would miss earth by 2,752,035,126 km Thats 2.7 thousand million kilometers at only One sixtieth of a degree misalignmed. I cant remember off hand, how wide the burst would be, i did read it, but you can see that at that distance, it does not take a lot to miss us.

I am not worried at least.

This post has been edited by Dundee: Mar 14 2008, 06:48 AM