What would the outcome if a supernova happened ten light years away from earth?

Question

Would we be incinerated,would it effect us in any way.

Answer 1

There are no candidate supernovas within 10 light years, fortunately, because it would probably wipe out all life on earth above the cellular level.

Answer 2

There are two types of supernovae: Type 1a and Type II. They are caused by two completely different processes, by two completely different types of stars.

A 1a is caused by a white dwarf sucking matter off a partner star in a multi-star system (two or more stars in close orbits around each other). Once enough matter (hydrogen) collects on the white dwarf's surface, it will "detonate" in a huge thermonuclear explosion, though the white dwarf itself, as well as it's partner stars, will survive this. One of these bad boys at over 3,000 light years can have a significant impact on Earth's atmosphere. This is also the most concerning type to humans since close by white dwarfs are difficult to detect since they are so small, and many could easily reside, undetected, well within 3,000 light years of Earth. Their explosions, timewise, are also extremely unpredictable.

Type II are extremely well understood, predictable, and their effects are much weaker. Type IIs are caused by the end of the life of certain classes of stars. We understand this cycle very well, and can predict when stars will go Type II. The good news is that one would need to be within only 30 light years, not 3,000 as with Type 1a, to affect Earth the same amount as a type 1a. We also know that there are no stars "scheduled" to go Type II within 30 light years of Earth for several hundred million years.

The effects of a Type 1a at about 3,000 light years and a Type II at 30 light years are roughly equal: considerable degradation of the ozone layer by about half for several years which allows gamma, ultra-violet and x-ray radiation, cosmic rays, and a lot of other nasty stuff to reach us, not to mention that it would also cause chemical reactions in the Earth's atmosphere would would create nitrogen oxides- some are very, very poisonous gasses that destroy your lung tissue. But the human race would likely survive either type at those distances.

If either type were to occur closer, the increased intensity of the effects could completely blow the atmosphere off Earth, killing us rather quickly, and boiling off the oceans. So if a Type 1a were to occur 10 light years away, this would likely happen. But if a Type II were to occur only 10 light years away, we would probably keep most of out atmosphere, but humans would probably die from acute radiation exposure.

Answer 3

We wouldn't know until 10 years later.

Answer 4

We would be harmed (but not necessarily incinerated).

If the star is a rapid rotator and the rotation axis is aimed our way, then we could get flooded with high energy radiation and that would be a very bad day.

Fortunately, there is nothing within 10 light years that can go supernova very soon (soon in astronomy is measured in millions of years).

Answer 5

First, calling it a "very bad day at the office" doesn't cover it.  But it would not kill all life on Earth.  The microbes found kilometers below the ground, and the others found near hydrothermal sea floor vents won't even notice.

But supernovae don't happen for just any star.  For example, Sirius is 8 light years away, but is only slightly more massive than the Sun.  It won't explode.  What you really want is a Wolf-Rayet star, with it's axis of rotation pointed at us.  From ten light years, that would really hurt.  The gamma ray burst alone could sterilize the life on half the planet.  And the damage to the ozone layer would be planet wide.  But fortunately, there aren't any stars like that nearby.

But it appears there is one. WR 104 is perhaps 8,000 light years away, and pointed at us.  Guess what the "WR" letters stand for?

We can't know if it has already exploded.  In fact, the way space-time works, there is no universal frame of reference for time.  It hasn't exploded.  If and when the light gets here, that's when it happens.  Fortunately, it might miss.  It might not even produce a gamma ray burst.  By the time it happens, we may be able to guess when, and put up some sort of shield.

I'm glad it's in Sagittarius, which is very low in the southern sky for me at the highest, and most of the time it's below my horizon.

Answer 6

Well, it depends how powerful the supernova is. If is strong enough to reach the earth, who can tell? Maybe we would be incinerated.

Answer 7

We wouldn't be incinerated but our magnetic field and our atmosphere would be stripped and we would be bombarded with massive amounts of radiation. We would die a rather horrible death.

Answer 8

it would severely damage our atmosphere and trigger a mass extinction.!!

Answer 9

An ordinary core collapse supernova or an exploding white dwarf that close would devastate our planet. The surge in x-rays and gamma rays would destroys much of the ozone layer, and the climate would be disrupted so profoundly that mass extinctions are sure to follow. The high levels of radiation from both the Sun and the supernova reaching the ground would trigger genetic mutations and other radiation related illnesses and causes of death. Cancer, fatal or acute radiation sickness, birth defects, blindness and starvation would be following. There would also be a smog layer from all the nitrous oxides created by the action of gamma rays ripping apart oxygen and nitrogen molecules in the atmosphere, allowing them to form oxides of nitrogen. In space, radiation would kill astronauts up there and either damage or destroy electronics aboard spacecraft and satellites. There could well be an electromagnetic pulse effect that would destroy all or most of the world's power grids. Transformers would blow apart from the massive power surges, and computers would also be wiped out. Unless the star that went supernova was our own Sun, which cannot become one, we would not incinerate.  It is possible however to die by incineration because of a supernova, if a rare kind of star explodes as a hyper-nova. If one of the hyper-nova's jets of gamma rays and high energy plasma were aimed precisely our way from 10 light years away, the atmosphere and oceans would boil away, the earth's crust and mantle would melt and be turned into a sea of lava. All life on Earth would be wiped out in seconds. A hyper-nova can explode with 100 times the energy of an ordinary supernova, with most of the energy focused into jets so powerful they can wipe out life on a planet 6,000 light years away. Fortunately, the nearest star that is anywhere close to exploding as a supernova is a white dwarf sucking in hydrogen from it's companion. Known as IK Pegasi, it's 150 light years away and when it does explode it will be a spectacular light show and a bonanza for astronomers, but otherwise harmless. Currently it's near the point where electron degeneracy can no longer support the white dwarf against it's own gravity. When that happens, the star collapses, then runaway nuclear fusion in the center begins. In less than a second the star is consumed and blows apart like a detonating thermonuclear bomb. Two other fairly nearby stars that are going to explode as core-collapse supernovae are Betelgeuse and Antares, which are red super-giants that have about 15 times the mass of the Sun. The nearest star that will explode as a hyper-nova is Eta Carinae, some 7,500 light years way. It is due to go off at any time in the next 10,000 or 100,000 years. When it does explode, it will very likely produce a black hole and spawn deadly jets of radiation and high energy plasma from the accretion disk that forms around it. However, the star's poles are pointed away from us, and we'll be safe.

Answer 10

If a nearby star went nova, our solar system would be flooded with hard radiation, and any life forms not protected would die.

Horrible, but theoretically survivable, especially if the earth was on the other side of the sun when the blast wave reached our solar system.

A SUPERnova?

We'd all die, no matter how well protected.  All of our sun's planets would be crisped into cinders, and even the sun itself might be consumed.