Supernova poised to go off near Earth

new scientist.com ^ | may-2-2002 | Eugenie Samuel ,new scientist

[lizma]

"But do not panic yet."

Of course not, I'm sure we'll all be killed by global warming before this occurs. Chill out, guys!

[IncPen]

Like a warming light at KFC... kewl

[green team 1999]

i think the sun (our sun)might give us a surprise one day

[jae471]

Of course, the thing could've blew 150 years ago, and we won't know until about 3 minutes before we all die tomorrow.

[spodefly]

But do not panic yet. "Very soon" could mean hundreds of millions of years in the future.

Still, I'm not buying an green bananas ...

[Mr. Mojo]

Fortunately, it will take time for HR 8210 to accumulate the mass it needs. Preliminary calculations by Rosanne di Stefano at the Harvard-Smithsonian Center suggest this may take hundreds of millions of years.

I hope an astronomer Freeper will help me out here, but I thought stars that are massive enough to become supernovae - a small number, comparitively - have very short lifespans, sometimes as short as only a few hundred thousands years. An star with "average" mass (such as our own), by comparison, has a lifespan of 5 to 10 BILLION years.

And where would it be "accumulating mass" from? Its stellar binary partner, perhaps?

[Arkinsaw]

Well, I guess that means I can run my credit cards all the way up.

[Calvin Locke]

suggest this may take hundreds of millions of years.... she still needs to confirm exactly how far. "I want to be sure I'm right."

Not that anyone would care in a million years, let alone until she confirms it, but I guess it's a 'hood that
NASA might think about twice about before colonizing.

[Calvin Locke]

"But do not panic yet."

I don't intend to [panic]. My "guide" has "DON'T PANIC" on it in nice big friendly letters.

[green team 1999]

aug-22-02,sun spot (our sun) 69,(right side) will generate a large solar x flare soon.

[<1/1,000,000th%]

If it did let fly, the high-energy electromagnetic radiation and cosmic rays it released would destroy Earth's ozone layer within minutes, giving life little chance of survival.

This doesn't sound correct. We're 8 light-minutes from our sun and we still have an ozone layer. This other object is 150 light-years away and it can focus more energy on us than the sun?

[green team 1999]

i don`t know,but let`s follow Calvin Locke advice,don`t panic,

[aBootes]

Close binary systems can end up as type I supernovae. Just before the explosion, the system consists of a white dwarf near the limiting mass and a companion of about 1 solar mass. As the companion becomes a red giant, the overflow of its stellar material (hydrogen-rich) begins to accrete onto the white dwarf. The hydrogen burns on the surface, producing a layer of helium that increases in mass. By the time the helium begins to burn to carbon, it does so under degenerate conditions. The temperature increases to the point where carbon ignites. When that happens the temperature increase so rapidly that an explosion is produced (the type I supernovae)and the carbon burns to nickel and iron which then causes the entire star to blow up. Typically there is no remnant. The light produced is primarily from the radioactive decay of nickel-56.

You are, I think, describing a type II supernovae which results from evolution of a single massive star.

[Mr. Mojo]

Check this out:

Gamma Ray Bursts and Supernovae

[MissAmericanPie]

According to the book of Revelation, it will.

[<1/1,000,000th%]

Nice link. Thanks.

[Mr. Mojo]

Thanks for the clarification and the detailed response. Which type of supernovae (type I or II) are more common?

[aBootes]

This doesn't sound correct. We're 8 light-minutes from our sun and we still have an ozone layer. This other object is 150 light-years away and it can focus more energy on us than the sun?

A type I supernovae can have a luminosity 10,000,000,000 times that of the Sun, depending on a couple of things. So yes, the predictions here regarding damage to the Earth are theoretically sound.

No supernova has been seen in our galaxy since the invention of the telescope. In theory, we are due for one -- have been from several hundred years.

[henbane]

IN 100,000,000 YEARS OR SO!