centauri explosion/implosion

[alexsciri]

If one of the centauri stars exploded/imploded would it effect our solar system?

[Mr Skeptic]

If there were a supernova anywhere nearby we would be toasted.

[Martin]

If one of the centauri stars exploded/imploded would it effect our solar system?

 

physically impossible for any star in the Centauri system to go supernova.

not massive enough

 

(that is, according to the accepted model of how stars go supernova---maybe with some new physics or some extremely unlikely event that contributes extra mass...)

 

however, in agreement with what Skeptic says, if there were a star that near us (like 4 or 5 lightyear) that DID have enough mass to put it on track to eventually go supernova, then people would be worried. I can't imagine how life could survive a supernova that close.

[Mr Skeptic]

Yeah, the whole outshining the rest of the galaxy combined thing is kind of scary. How close could a supernova be for the human race to survive?

 

Is there anything we could do to increase our odds of surviving a supernova? Perhaps build a bunker at the center of the moon?

 

Please tell me the astronomers can give plenty of advance warning if a nearby star was about to go nova.

[insane_alien]

well, if we sheltered behind the earth(impractical since we would have to keep it up for decades, unless it is over one of the poles) we could maybe survive. we could tell it was coming as the star in question would probably swell enough to have a visible disk before it decided to go the whole hog and go down swinging.

[Spyman]

Impact on Earth

 

A near-Earth supernova is an explosion resulting from the death of a star that occurs close enough to the Earth (roughly fewer than 100 light-years away) to have noticeable effects on its biosphere. Gamma rays are responsible for most of the adverse effects a supernova can have on a living terrestrial planet. In Earth's case, gamma rays induce a chemical reaction in the upper atmosphere, converting molecular nitrogen into nitrogen oxides, depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation. The gamma ray burst from a nearby supernova explosion has been proposed as the cause of the end Ordovician extinction, which resulted in the death of nearly 60% of the oceanic life on Earth.

 

Speculation as to the effects of a nearby supernova on Earth often focuses on large stars as Type II supernova candidates. Several prominent stars within a few hundred light years from the Sun are candidates for becoming supernovae in as little as a millennium. One example is Betelgeuse, a red supergiant 427 light-years from Earth. Though spectacular, these "predictable" supernovae are thought to have little potential to affect Earth.

 

Recent estimates predict that a Type II supernova would have to be closer than eight parsecs (26 light-years) to destroy half of the Earth's ozone layer. Such estimates are mostly concerned with atmospheric modeling and considered only the known radiation flux from SN 1987A, a Type II supernova in the Large Magellanic Cloud. Estimates of the rate of supernova occurrence within 10 parsecs of the Earth vary from once every 100 million years to once every one to ten billion years.

 

Type Ia supernovae are thought to be potentially the most dangerous if they occur close enough to the Earth. Because Type Ia supernovae arise from dim, common white dwarf stars, it is likely that a supernova that could affect the Earth will occur unpredictably and take place in a star system that is not well studied. One theory suggests that a Type Ia supernova would have to be closer than a thousand parsecs (3300 light-years) to affect the Earth.

http://en.wikipedia.org/wiki/Supernova

 

 

Exploding Stars: Threat to Earth Lower But Still Real

 

Researchers have suggested that one or more mass extinctions during the past few hundred million years might have been triggered by supernovae, and that it might happen again.

 

But a new and detailed set of calculations shows that such events are probably extremely rare.

 

The study, led by Neil Gehrels of NASA's Goddard Space Flight Center, found that for a supernova to significantly deplete ozone it would have to occur within 26 light-years of our planet. Other data shows that this happens only about once in a billion years.

http://www.space.com/scienceastronomy/supernova_threat_021216.html

 

 

Cosmic Cannon: How an Exploding Star Could Fry Earth

 

Stanford E. Woosley, an astrophysicist at the University of California, Santa Cruz, said that even from the far side of our galaxy, a GRB would be as bright as the Sun -- not in visible light, but in gamma rays. Luckily, most gamma rays -- all but the highest energy versions -- do not penetrate Earth's atmosphere. But the visible light does.

 

"Something this intense would create an optical flash by scattering electrons in the upper atmosphere and creating something like a super-aurora," Woosley said. It's an idea he's working on but has not yet published.

 

"The flash of heat and light might flash-burn anything not in the shade," he said. "Heating the atmosphere would cause big winds. The air would be much hotter for weeks, as hot as an oven depending on the distance. This would affect the other side of the Earth eventually."

http://www.space.com/scienceastronomy/astronomy/gammaray_bursts_010522-1.html

 

 

Hypernova

 

Hypernova (pl. hypernovae) refers to an exceptionally large star that collapses at the end of its lifespan—for example, a collapsar, or a large supernova. Up until the 1990s, it had a more specific meaning to refer to an explosion with an energy of over 100 supernovae (10^46 joules). Such explosions were proposed to explain the exceptional brightnesses of gamma ray bursts. An extensive sky search found several apparent hypernova remnants, but the frequency was too low to support the hypothesis. Today the term is used somewhat more prosaically to describe the supernovae of supermassive stars, the hypergiants, which have masses from 100 to 150 times that of the Sun. Hypernovae can pose serious threats to Earth in terms of radiation output, but no stars capable of creating hypernovae are located near Earth.

http://en.wikipedia.org/wiki/Hypernova

[Mr Skeptic]

Wow. Thanks, Spyman