'Death Star' Aimed at Earth 400
An anonymous reader writes "A spectacular, rotating binary star system is a ticking time bomb, ready to throw out a searing beam of high-energy gamma rays that could lead to a major extinction event — and Earth may be right in the line of fire. Australian science magazine Cosmos Magazine reports: '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.'"
Atmosphere? What atmosphere? (Score:4, Interesting)
Re:I asked GOD (Score:3, Interesting)
Whip out your concordance. The Hebrew word for "day" used in Genesis isn't meant to be metaphorical; it's a literal, 24-hour period of time.
If you assume that everything in the Bible is no deeper than a convoluted historical document, you're missing a lot.
Re:Thanks guys (Score:4, Interesting)
Which leads us to the interesting question: If we knew we were in danger and had 100,000 years to do something about it, what would be the simplest solution?
1) Move everybody somewhere else
2) Put up shields
3) Move the Solar system out of the way
4) Point the Supernova at the Arcturans instead
Re:Thanks guys (Score:3, Interesting)
Gamma rays don't suddenly stop dead in their tracks at 6500 light years, nor do they dissipate that fast. Gamma rays are light and the fact that we can see this star (and those thousands of times further away) indicates that if a large burst of gammas was flung in our direction we'd be well in the path. There was a recent episode of The Universe that covered this possibility. Nothing we can do about it however.
Re:Atmosphere? What atmosphere? (Score:3, Interesting)
What it really lacks is a dense atmosphere...It's only about 1/100th as dense as ours. It would be interesting if it were a little denser, because the atmosphere is almost completely CO2. In composition, it is much heavier than our primarily nitrogen atmosphere, and it does lend weight to the idea that the bulk of the "light" elements in the atmosphere have been stripped away, though it's equally likely, especially in the case of things like H2, that they just "escaped"...It doesn't take much to accelerate hydrogen to escape velocity when the gravity is that low. Even on earth we lose a measurable amount.
Re:I asked GOD (Score:2, Interesting)
Some questions...anyone with answers? (Score:-1, Interesting)
How will our motion around the galaxy, relative to where this star system is, change our perspective on these binary stars?
If we are "looking down" on it now, will our position in the galaxy change with time sufficiently to reduce the impact?
(Note that over a long enough period of time, the appearance of constellations in the sky that we see every night will change.)
How does the GRB disburse over distance?
At 8000ly, what is the area covered by the flat end of the cone vs 8, 80 and 800ly?
Re:OH NOES (Score:3, Interesting)
The point I was trying to make was that a star just doesn't go supernova from a normal star with no 'warning' Of course, the last phase just before it reaches the Chandrasekhar limit is very short, and the subsequent collapse IS effectively instantaneous.
But it shows that the star does go through a 'series' of collapses. It was those collapses that I was clumsily referring to as giving off indicators.
For example, if the star did go nova '7999' years ago, then we would see that it was already burning carbon which would be a pretty good indicator that we were set for a light show.
The real question I have is why the astronomers seem to think that the supernova event is so near, yet outside of the normal timeline by which they should be able to determine that it is so near. If it was burning Helium, you could expect it to last one to one million years. But if it was already on Carbon, then you could be fairly certain that it would only be a few thousand at most.
This is just guessing on my part, but I wonder if they are only detecting that it is burning Helium, but that the combination of the second star in the system is 'feeding' the WR star, causing its 'life' to accelerate.