What If There was a Super Nova on Alpha Centauri? Or any star 4.3 light years away.

[Amanda Siebe]

Hi,

First of all I am new to the forum. So greetings. I have a question that is probably kind of weird. I know Alpha Centauri is the closest star to the Sun. I also know that it is not
a Red Giant or Super Giant star. Not nearly yet. So the time for Alpha Centauri (A and B) to end its life is millions and millions of years away. But as a hypothetical. Or actually maybe the question would be better if there was a Star near the end of its phase a Red Giant and approximately the same distance away as Alpha Centauri and it did super nova. Like some time around the now time frame. What would happen. And what would the implications of that be to us?

I know that the light from the Super Nova wouldn't reach Earth until Four years away after it happened. And I am guessing that the event itself would be as bright as the Full Moon in the sky. And definitely lasting. In both the night and the day time. But would anything harmful happen to Earth or our Solar System. Like as we saw the super nova would there be like a shockwave or damaging Ultraviolet radiation or something akin to Solar flares (in the visible or invisible light spectrum.) that would alter life on earth.

Also, this is the harder question I am guessing. But would debris from that Super Nova eventually come to earth or be a danger to our solar system. I am guessing the debris would take tens of thousands of years to get here after the event. I am guessing since we have this ridiculous news cycle now, where it's impeach impeach impeach, war, war, war, they keep it going every day. Would something like a Super Nova happening in the range of a Alpha Centauri be a continuous deal, like literally never ending in the news—like for hundreds of years. Because they knew that some level of damage would come eventually. And then another level of potential damage — eventually.

Like ok now guys, the worst thing is just seeing this really bright spectacle in the sky and get used to it because it is going to be a normal sky artifact.. But no danger.

A thousand years later.. Ok now guys remember that Super Nova (that you can still see visible) expect this to potentially happen.

A thousand years later.

And so forth.

I am a novice on this subject. And I know this is purely fiction. But it is something I think is interesting. And at least a relevant question to other stars in the Galaxy that may be close to a star that is about to super nova. I would think that for sure their would be a shockwave that could disrupt the orbits of the planets. But I am really clueless on how quickly that shockwave would come.

Thanks

Grimpachi

[antoniseb]

...if there was a Star near the end of its phase a Red Giant and approximately the same distance away as Alpha Centauri and it did super nova. Like some time around the now time frame. What would happen. And what would the implications of that be to us? ...

It would be very bad. The supernova would release 10^53 ergs, and and is 4x10^18 cm away, so 4 pi r^2 we would be at a place getting 5x10^14 ergs per square cm spread out over a few months. The atmosphere would be stripped away and the oceans would boil. If you hid deep underground the bath of neutrinos would make your flesh and everything around you highly radioactive. Thousands of years later, some debris would hit the dry dead cinder of a planet that we used to live on.

[Jens]

I know that the light from the Super Nova wouldn't reach Earth until Four years away after it happened. And I am guessing that the event itself would be as bright as the Full Moon in the sky.

Just adding an interesting fact to the previous post, but actually, it would be much, much brighter than that. There is talk now about the possibility that a relatively nearby star (Beetelgeuse) might go supernova, and it is 640 light years away, but still will be brighter than the moon when it explodes.

[StupendousMan]

You can find a list of the possible dangers from relatively nearby supernovae, and some references for further reading, in this document:

http://spiff.rit.edu/richmond/answers/snrisks.txt

If a star at just one parsec (roughly the distance of Alpha Centauri) were to explode as a Type II supernova, as Betelgeuse will someday, then it would appear in our sky -- at its peak -- only slightly fainter than the Sun; maybe one-twentieth to one-fiftieth the brightness of good ol' Sol. For many purposes, the night would appear almost as bright as the day, for a few weeks.

[Van Rijn]

Hi,

First of all I am new to the forum. So greetings. I have a question that is probably kind of weird. I know Alpha Centauri is the closest star to the Sun. I also know that it is not
a Red Giant or Super Giant star. Not nearly yet. So the time for Alpha Centauri (A and B) to end its life is millions and millions of years away.

Billions of years. Also, they aren’t massive enough to go the supernova route. It is still an interesting question about the effects of a nearby supernova, but we don’t have to worry about the Alpha Centauri stars.

[Tom Mazanec]

Here's a fun one:
Pretend Gliese 710 is a supernova progenitor that goes off in 1,283,000 AD.
Would Earth be sterilized?

[Amanda Siebe]

Ah, antonisb. Enough of the Landauer-Buttiker formalism. But you could be right. Eh Gee. Or how many earths have already been. Is Gliese 710 a star that is hosting one of those "mask up" planets? A couple of problems with that telemetry if everyone on earth is already sterilized because we aren't allowed to have kids because we don't want to infect other people. Alien days are coming, says Susan Hendricks. As you think apples to apples or as you think apples to a Gliese. Well antonisb — some debris. Could it fill that crater in Arizona?? A quasar hitting earth may be even several more millions of years away. Unless you count the Covid Pandemic as one. No one does it like the honey bees, they're the best, says Nicholas Sarro. Hypothyroidism. And then you have Covid (in other words sex with animals.) Autism spectrum, says Chris Cuomo.

My best guess about all of this is basically more of an unguess. I mean if Knute Rockne comes to your mind first when someone says what comes to your mind first when you think of football. I know that if my mom and dad had one sit down and drink wine session with Donald Trump (or as my mom basically just now admitted, even with Donald Trump's kids) That they would come away not saying Knute Rockne or Darral Royal, but Mike Ditka.

Yup, the A.C. can the Antichrist get your own parents. Yes sir. In the meantime. Also I know what NASA (that degraded Agency) is going to try to do. Or set up.

The Pluto and Charon photos. Probably they are New Horizons. Probably. Probably not Farrah Fawcett's ex-lover, in command of a black triangle.

[DaCaptain]

It would be very bad. The supernova would release 10^53 ergs, and and is 4x10^18 cm away, so 4 pi r^2 we would be at a place getting 5x10^14 ergs per square cm spread out over a few months. The atmosphere would be stripped away and the oceans would boil. If you hid deep underground the bath of neutrinos would make your flesh and everything around you highly radioactive. Thousands of years later, some debris would hit the dry dead cinder of a planet that we used to live on.

Is there any kind of shield we could make to protect us?

[eburacum45]

Going underground would be the best shielding. Then all we have to worry about is the neutrinos, and rebuilding our entire biosphere and atmosphere afterward. Do we have an estimate for how damaging the neutrino irradiation would be?

[Grey]

Going underground would be the best shielding. Then all we have to worry about is the neutrinos, and rebuilding our entire biosphere and atmosphere afterward. Do we have an estimate for how damaging the neutrino irradiation would be?

We should be safe from neutrinos at that range.

[Grey]

It would be very bad. The supernova would release 10^53 ergs, and and is 4x10^18 cm away, so 4 pi r^2 we would be at a place getting 5x10^14 ergs per square cm spread out over a few months. The atmosphere would be stripped away and the oceans would boil. If you hid deep underground the bath of neutrinos would make your flesh and everything around you highly radioactive. Thousands of years later, some debris would hit the dry dead cinder of a planet that we used to live on.

I'm not quite sure it would be as bad as this. A typical core collapse supernova does release about 10⁵³ ergs (100 foe), but almost all of that is in the neutrino burst, and the xkcd link above (and the actual paper it's based on suggest that the amount of radiation from that won't be anything serious at a parsec. That's not too surprising; even though the amount of energy is large, the interaction cross section is small, so most of those neutrinos will pass effortlessly through the Earth.

The kinetic energy is typically closer to 1 foe, but that shock wave will reach us after many years, and I'd expect rather spread out in time and diffused by its travel through the interstellar medium.

The radiation (visible, x-rays, and gamma rays) is the part that will hit us first, but that is typically only about 0.01 foe, so now we're talking about 5 x 10¹⁰ ergs/cm².

We get about 1.3 x 10⁶ ergs/cm² from the Sun every second. So over a period of 3 months, that works out to around 10¹³ ergs/cm², and so our nearby supernova has boosted the radiation Earth receives by less than a percent for a few months. I'm sure that would have noticeable effects (especially on living things, since a good portion of that would be gamma rays), but I don't think it would actually blast the atmosphere away and boil the oceans. I think Spiff's document has a similar conclusion.

[Roger E. Moore]

I recall there was concern about a muon rain from a very close Type Ia supernova.

[DaCaptain]

Going underground would be the best shielding. Then all we have to worry about is the neutrinos, and rebuilding our entire biosphere and atmosphere afterward. Do we have an estimate for how damaging the neutrino irradiation would be?

The shield i was thinking about would be space based. Put some sort of “reflector” between earth and the super nova. If we see the super nova is it already be to late to do anything or would exposure damage take a while to build?

[kzb]

I recall there was concern about a muon rain from a very close Type Ia supernova.

I recall you found a paper on this a few years back. My recollection was that the muons would not be lethal.

The biggest concern with nearby supernovae is meant to be the destruction of the ozone layer. The gamma rays hitting the atmosphere create nitrogen oxides which then react with ozone.

Without our ozone layer, plant life (the base of the foodchain) gets fried with short wavelength UV from the sun (NB not the supernova itself). With no plants to eat, animal life obviously takes a big hit.

Basically it is a extinction level event for higher animals, resetting evolution back hundreds of millions of years.

I recall the effective range for this is up to a few parsecs, so one at Alpha Centauri distance could well have this effect on our planet. But do notice it is not the direct radiation from the SN itself that is the hypothesised problem, it's the UV from our own sun.

[Roger E. Moore]

I recall you found a paper on this a few years back. My recollection was that the muons would not be lethal.

The biggest concern with nearby supernovae is meant to be the destruction of the ozone layer. The gamma rays hitting the atmosphere create nitrogen oxides which then react with ozone.

Without our ozone layer, plant life (the base of the foodchain) gets fried with short wavelength UV from the sun (NB not the supernova itself). With no plants to eat, animal life obviously takes a big hit.

Basically it is a extinction level event for higher animals, resetting evolution back hundreds of millions of years.

I recall the effective range for this is up to a few parsecs, so one at Alpha Centauri distance could well have this effect on our planet. But do notice it is not the direct radiation from the SN itself that is the hypothesised problem, it's the UV from our own sun.

Here is one paper on the lethality of muons from a 50-parsec supernova.


https://arxiv.org/abs/1702.04365

A supernova at 50 pc: Effects on the Earth's atmosphere and biota

A.L Melott (Kansas), B.C. Thomas, M. Kachelriess, D.V. Semikoz, A. C. Overholt

Recent 60Fe results have suggested that the estimated distances of supernovae in the last few million years should be reduced from 100 pc to 50 pc. Two events or series of events are suggested, one about 2.7 million years to 1.7 million years ago, and another may at 6.5 to 8.7 million years ago. We ask what effects such supernovae are expected to have on the terrestrial atmosphere and biota. Assuming that the Local Bubble was formed before the event being considered, and that the supernova and the Earth were both inside a weak, disordered magnetic field at that time, TeV-PeV cosmic rays at Earth will increase by a factor of a few hundred. Tropospheric ionization will increase proportionately, and the overall muon radiation load on terrestrial organisms will increase by a factor of 150. All return to pre-burst levels within 10kyr. In the case of an ordered magnetic field, effects depend strongly on the field orientation. The upper bound in this case is with a largely coherent field aligned along the line of sight to the supernova, in which case TeV-PeV cosmic ray flux increases are 10^4; in the case of a transverse field they are below current levels. We suggest a substantial increase in the extended effects of supernovae on Earth and in the lethal distance estimate; more work is needed.This paper is an explicit followup to Thomas et al. (2016). We also here provide more detail on the computational procedures used in both works.

And another on lethal muons.

https://arxiv.org/abs/astro-ph/9705008

Life Extinctions By Cosmic Ray Bursts

Arnon Dar, Ari Laor, Nir J. Shaviv

High energy cosmic ray jets from nearby mergers or accretion induced collapse (AIC) of neutron stars (NS) that hit the atmosphere can produce lethal fluxes of atmospheric muons at ground level, underground and underwater, destroy the ozone layer and radioactivate the environment. They could have caused most of the massive life extinctions on planet Earth in the past 600 My. Biological mutations due to ionizing radiations could have caused the fast appearance of new species after the massive extinctions. An early warning of future extinctions due to NS mergers may be obtained by identifying, mapping and timing all the nearby binary neutron stars systems. A warning of an approaching cosmic ray burst from a nearby NS merger/AIC may be provided by a very intense gamma ray burst which preceeds it.

[kzb]

Here is one paper on the lethality of muons from a 50-parsec supernova.


https://arxiv.org/abs/1702.04365

A supernova at 50 pc: Effects on the Earth's atmosphere and biota


And another on lethal muons.

https://arxiv.org/abs/astro-ph/9705008

Life Extinctions By Cosmic Ray Bursts

The second paper is not about supernovae. It is about neutron-star mergers. There are three known neutron-star pairs in our galaxy, all at >kpc distances, and when they merge we have to be unlucky enough to get caught in the tightly collimated radiation beam. So I won't be lying awake worrying about that.

The first paper is about supernovae, and argues that the SN lethal range should be increased to 50pc. But this is based on considerations of the cosmic ray flux to the atmosphere, reducing ozone by 66% and thereby increasing short-wave UV penetration of the atmosphere to lethal levels.

Granted there is a substantial increase in radiation dose from muons. But at this range (50pc) it is not enough for acute radiation effects to become apparent. Wild animals don't live long enough to get cancer, so the effect on the biosphere is pretty much non-existent. It would not be very good for us humans though, substantially increasing our lifetime cancer risk. But the paper is quite clear the mass extinction event is due to the depletion of the ozone layer, not muons. It has to be said though, that at Alpha-Centauri distance, the muon radiation dose rate would be much more problematic.

Anyhow, the fact that different studies come up with such disparate results for the SN lethal range (a previous paper found 5pc; this one fids 50pc) tells me this is an evolving field. There are a lot of uncertainties to cope with in making these estimations.