How would we experience a nearby hypernova?

[Moonhead]

Suppose Sirius (A) was a hypergiant like Eta Carinæ, what would it be like if it blew up as a hypernova.

Would we be vaporized? Or would we see a very bright light and feel heath and die of radiation disease within hours or so?

How close could such a hypernova be without a catastrophy for life on earth?

[Twinsun]

don't even wanna think about it ... it's like the Apocalypse

[01101001]

PBS Nova Transcripts: Death Star

NARRATOR: Their deadly radiation flared through entire galaxies. What would happen if such an event took place near Earth?
[...]
[Arnon Dar:] [...] Say that the gamma ray burst occurs in our galaxy, and let's say that it occurs in that direction. Then the first thing that you would see when the flash of gamma rays arrive to our atmosphere you see a big flash of blue light, tremendous effects which are very similar to those which are when you are standing very close to a nuclear explosion. You would become blind in a very short time. Your skin will be completely burned. Your body will be burned and will be exposed to an enormous dosage of radioactive radiation, which will kill you in a very short time.

NARRATOR: And the same thing would be happening simultaneously all around the planet: a tremendous shock wave causes devastation; the sea boils; hurricanes spread deadly radiation around the globe. All but the most sheltered species are destroyed. The ozone layer is blasted away. And, unprotected, the earth turns under a continuous barrage of deadly cosmic rays.

STAN WOOSLEY: If you had it within just a few hundred light years, it would be sort of like Hiroshima going off all over the world all at one time. But in the whole galaxy there is nothing within a thousand light years that we would expect to produce a gamma ray burst anytime in the future.

Armageddon Online: Hypernova

What would happen if a hypernova occurred near Earth?

If a hypernova were to occur within 3,000 light years from Earth it could easily wipe out all life on the planet, even bacteria. If the Earth were within the path of one of the energetic cones the interactions of the gamma rays in the upper atmosphere would produce a lethal dose of highly penetrating ionized particles, destroying life on the surface, underground and underwater. The initial bombardment would immediately destroy the ozone layer and detonate the atmosphere akin to that of the simultaneous discharging, at the bare minimum, of one-kiloton of TNT per km^2, over the whole hemisphere facing the phenomenon. Ionization, the separation of atoms via gaining energy and losing electrons, would take place converting the oxygen and nitrogen in the atmosphere into nitrogen dioxide. Before covering the Earth in a black cloud comparable to that of urban smog, the sky would burst into flames and fireballs, creating global storms of acid rain and possibly fire. However, before all of the previous occurred, the actual radiation would hit the surface. The radiation energy level would be roughly around 10^4 to 10^7 eV (electron volts). If compared to a standard medical x-ray machine's 200,000 eV (and needing a protective lead vest), you get up to 1 million times the radiation! Radiation affects high atomic-number elements more. The most abundant high atomic-number elements in biological organisms are calcium and potassium. These two elements are utilized in muscle function, and ionizing radiation would cause extreme cramping of muscles, making a rather stiff and painful, but quick death.

[Moonhead]

PBS Nova Transcripts: Death Star

Cool, thanks!

Now I'm reading the excerpts, I must disagree with Twinsun. This happens a lot faster than the Apocalypse (the biblical one, that is).

[Moonhead]

Take into account its distance and the only thing that would happen if Eta Carinae went hypernova is that Earth-bound observers would see the increase in luminosity and satellites in the southern hemisphere would be fried.

source: http://www.armageddononline.org/hypernova.php

Maybe NASA should wait building their Lunar Outpost until Eta Carinæ went off....

[antoniseb]

Only if the beam was in our direction... It appears that Eta Carinae is not pointed in our direction.

[m1omg]

Armaggedon Online is wrong at one thing - the hypernovae is not a hypothetical phenomenon but a real, observed one, for example Sn2006gy was a REALLY powerful one but 150 megaly distant...still it outshined it's galaxy in hard radiation..

[m1omg]

PBS Nova Transcripts: Death Star



Armageddon Online: Hypernova

Well except bacteria living kms underground...
And radiodurans and the other one radioresistant guy may even survive deep underwater.

[Noclevername]

Armaggedon Online is wrong at one thing - the hypernovae is not a hypothetical phenomenon but a real, observed one, for example Sn2006gy was a REALLY powerful one but 150 megaly distant...still it outshined it's galaxy in hard radiation..

Gamma bursts have been observed, the hypothesis is that they're caused by hypernovae.

[m1omg]

Gamma bursts have been observed, the hypothesis is that they're caused by hypernovae.

But SUPERNOVA 2006GY was a REAL HYPERNOVA, NOT GRB.
The core of that star was entirely converted to approx. 40 solar masses of nickel and that explosion was VERY POWERFUL/
The progenitor star was in the range of 100-200 Solar masses.

[trinitree88]

But SUPERNOVA 2006GY was a REAL HYPERNOVA, NOT GRB.
The core of that star was entirely converted to approx. 40 solar masses of nickel and that explosion was VERY POWERFUL/
The progenitor star was in the range of 100-200 Solar masses.

Which reminds me of securing my patent rights on a sunscreen with factor 88,888,888 .( I like 8's.)..it's my lucky number. Ozone by the way is created in an equilibrium with molecular oxygen, depleting it causes it to form faster...Le Chatelier's Principle....so after the GRB, it won't take centuries to reform, and the dissociation of molecular oxygen into atomic oxygen is also an equilibrium condition with a high rate of formation of the molecules. The neat part is that nitrogen combining with oxygen in a variety of oxides would poison the atmosphere by combining with the water vapor to make nitric acid. (they had some concerns about igniting the atmosphere when they set off the first hydrogen bomb, but they did it anyway).pete.

[afterburner]

Very interesting.

I think that the real question is...How far away, and how strong would a supernova have to be, so that here on Earth, we would classify its effects on us as mildly inconvenient, but definitely survivable.

It would be nice to have a graph with "distance from Earth" and "supernova strength/class" for an even that would wipe out all life, and then have color schemes/overlays that have a scale going from "all life destroyed" to "mildly inconvenient afternoon". And then perhaps a different overlay with probabilities, and even time scales, for these events actually happening, based on real, observational data collected so far.

[Twinsun]

hmm we can make a formula based on the star's energy, luminosity, size, mass and distance from the Earth ... I'll try tomorrow