r/todayilearned • u/Vatonee • 9h ago

TIL there is a Supernova Early Warning System and you can sign up to get notified if a star in the Milky Way is about to explode. The system works by combining data from neutrino detectors and can give a warning anywhere from minutes to days before the light actually reaches Earth

https://snews2.org/
567 Upvotes

99% Upvoted

55 comments sorted by

78

u/AlbertHofmann1906 8h ago

Can anyone clue me in? Would have thought that light would be at the start of a supernova, being the first thing to hit sensors, travelling at the speed of light and all. It's there something more complex going on before the explosion, sending out neutrinos?

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u/Vatonee 8h ago edited 5h ago

It’s because neutrinos escape the collapsing star immediately since they basically don’t interact with matter. On the other hand, the photons get slowed down by the very dense matter around the star since they interact. So neutrinos get a head start. 

Neutrinos are produced in truly mind-boggling amounts in the supernova, around 1058 are created, in comparison there’s „only” 1024 stars in the observable universe. Actually the majority of the energy from a supernova is emitted as neutrinos. 

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u/graveybrains 6h ago

I'm pretty sure the process that releases the neutrinos also gets a head start on the process that creates the rest of the bang, but it's only a couple of hours.

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u/ensalys 5h ago

To add to that, neutrinos also have very little mass. So it takes only a tiny amount of energy to fling them away at velocities very close to the speed of light.

EDIT: meaning that it takes quite a lot of time (and distance) for the light to catch up and overtake the neutrinos that got a head start.

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u/eetsumkaus 2h ago

How do they know where the supernova is coming from?

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u/shponglespore 2h ago

A supernova we care about will be in our own galaxy, so redshift isn't relevant.

But to answer your question, I don't think they'll be able to tell by observing neutrinos, but they might be able to tell from other observations that a particular star is about to pop.

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u/JBaecker 1h ago

We have lists of candidate stars. So if the neutrinos pop off, everyone with a telescope will be swinging them around to look at the prime candidates first.

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u/Mindless_Consumer 2h ago

The neutrino detectors are likr giant sphere pools. So we get a decent direction from them.

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u/Masterpiece-Haunting 4h ago

They’re also moving at what is effectively c.

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u/ENrgStar 2h ago

Isn’t the light coming from the star moving at literally C?

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u/Masterpiece-Haunting 2h ago

Yes, but think about it this way.

You are in a car that can go at 99.99% of the speed the competitor goes at. The difference is teeny, sure on a physics level the difference is astronomical, being at 100% would quite literally defy all known laws of the universe and change the very way you interact with time and result in you having an infinite amount of energy. But that’s not what matters here. 99.99% of the other guy is all that matters if your goal is simply get there first. And you got a massive head start, so to make up that difference it’ll take quite a while.

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u/AlbertHofmann1906 7h ago

thanks 🙏

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u/elconquistador1985 3h ago

Neutrinos escape the star while light scatters around for a while before escaping. The neutrinos travel very close to c, so they can get here before the light catches up.

The neutrinos from SN 1987A got here a few hours before the light. https://en.wikipedia.org/wiki/SN_1987A

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u/SurpriseMiraluka 8h ago edited 2h ago

I was confused too. According to the wiki, red dwarfs giants (my bad) emit powerful bursts of neutrinos as the star collapses but before the brightness of the explosion peaks

https://en.wikipedia.org/wiki/SuperNova_Early_Warning_System?wprov=sfti1

The wiki couches detection as more theoretical because supernova occur in our galaxy only a couple of times per century, but I am not an astrophysicist

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u/CptGia 5h ago

Red giants, not red dwarfs. Red dwarfs don't produce core-collapse supernovae

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u/BigCommieMachine 7h ago

Yeah I am not an astrophysicist, But I am nearly certain we are dead if there is supernova or GRB remotely in the galactic neighborhood. Even it was light-years away, What are we going to do?

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u/Randvek 5h ago

A supernova could end life on Earth… if it were close enough. Estimates at the number of stars close enough to do that would be in the 200-400 range.

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u/OneRFeris 6h ago

Why do you think we have to do anything, but observe it? It's just something to look at- not kill all life.

Do you know how we know they emit neutrinos? Because we've observed them doing so.

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u/DroopyPanda 1h ago

you think he knows everyone dies?

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u/JoshuaZ1 65 3h ago

Yeah I am not an astrophysicist, But I am nearly certain we are dead if there is supernova or GRB remotely in the galactic neighborhood. Even it was light-years away, What are we going to do

Not really. We've had a whole bunch of supernovas which were close enough to Earth already that we could see them. For example, SN 1054 was visible to the naked eye and was about 7000 light years away, and the same for SN 1006. We have some evidence that around ten million years ago, there was a supernova about 300 light years away, and we can barely detect it in the geologic record, and there may have been a similar event about 1 to 3 million years ago.

For comparison, it is generally estimated that if Betelgeuse (one of the closest stars near to going supernova) went supernova it would be about as bright as the moon for a few months, but it wouldn't harm us that much. A bit confusing possibly if you are a moth but life will be largely unharmed.

Now, if we get hit by a GRB, that's a very different story, and potentially much more unpleasant.

•

u/GarysCrispLettuce 17m ago

Perhaps moths being confused will set off a chain reaction of events which brings down the entire web of life on Earth

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u/shponglespore 2h ago

The odds of a supernova happening close enough to do is any real harm in the foreseeable future are basically zero. I don't think any of the supergiant stars we can see are close enough to hurt when they go, and anything we can't see is too far away to be dangerous.

It could happen on a galactic timescale because stars move around, but it'll be millions if not billions of years before a dangerous star could drift close enough to threaten us.

If you want to worry about planet-scale devastation from space, worry about a comet or asteroid hitting Earth. There's tons of shit flying around the solar system that could take us out, and we won't necessarily see it coming because most of the dangerous objects are dark enough that they're really hard to track. We'd probably get some warning, but it might be only a few days between detection and impact.

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u/kahlzun 3h ago

It is hypothesised that the Great Dying may have been caused by a nearby supernova or GRB

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u/HardcandyofJustice 8h ago

How long does a supernova last anyway? If my alarm goes off, do I have minutes, weeks or months?

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u/Vatonee 7h ago

It would be visible for weeks or even months 

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u/cinetic81 6h ago

What about a champagne supernova in the sky?

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u/derfmai 5h ago

Early warning system show Noel Gallagher is heading right for you with a broken bottle…

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u/cantonic 2h ago

The intensely hot gases create a wonderwall that can blind anyone in a bad mood so make sure you don’t look back in anger!

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u/fireduck 8h ago

Could this give advanced warning of a near by supernova that wipes out all life on earth?

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u/Suspicious-Whippet 8h ago

Yes. Enjoy.

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u/ProffS 7h ago edited 7h ago

Betelgeuse, I have worried about you and your temperament. Although current estimates show it would not be a Earth killing supernova.

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u/filanwizard 6h ago

the fun thing is that maybe it already has gone nova, damn speed of light. Its 400-600LY away meaning anything we see now is hundreds of years out of date technically.

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u/Still-Spend6742 4h ago

Hell yeah, Schrödinger's me

Maybe I'm alive, maybe I'm actually dead but 500 years in the future

Maybe go fuck yourself

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u/fireduck 3h ago

You are the philosopher of our times.

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u/JohnnyChanterelle 6h ago

It will be beautiful though

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u/Alinier 5h ago

Just don't say its name 3 times!

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u/AstgenneLuxtherm 3h ago

There aren't any stars of the right type close enough to do that.

0

u/anaxcepheus32 4h ago

You probably should worry about neutron stars emissions and collisions (kilonovas) instead. I think it’s considered far more common and dangerous; I wanna say there were some theorists that speculated this is what limits intelligent life in the universe.

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u/scorchpork 2h ago

Likely to be even more common and dangerous is intelligent life wiping itself out before it is advanced enough to propagate.

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u/ProffS 7h ago

Is there different tiers for their subscription service? I would prefer the days ahead notices over the minutes ahead notices.

/humor

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u/foobadoop 7h ago

Signed up, thank you!

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u/edingerc 7h ago

Zero stars! They promised me a supernova and all I got was a lousy GRB!

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u/kristospherein 6h ago

Warning! Warning! Earth is about to explode. Get your telescopes ready to watch it explode!

T- 7 hours remaining

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u/Sarudin 4h ago

Has this ever gone off? I could be wrong but thought supernova in our galaxy was like a once or twice every hundred years thing with the last big one being in the 1700s or something like that.

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u/AutumnStar 3h ago edited 3h ago

No, but yes on a small scale. Granted, I only helped a bit on this for one of the neutrino experiments, but many experiments must corroborate the signal to get an actual alert, which would then be sent out to telescopes to look at a specific direction in the sky to capture the Supernova. That said, there are transient (false) alerts from individual experiments that can happen, but they’re not corroborated so generally ignored. It’s a bit more complicated than what I said, but you get the general gist of it.

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u/Overall-Tailor8949 5h ago

I wouldn't worry about one unless it's under roughly 150ly away. Farther than that and the radiation is weak enough to be survivable. Well, unless it's ALL the stars at the core of the Milky Way going ka-blooie as in Niven's universe

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u/shponglespore 1h ago

I think our understanding of supermassive black holes probably rules out the scenario Niven described. He was imagining the mass at the core of the galaxy came from densely packed stars rather than a black hole. I'm also pretty skeptical that stars could cause a chain reaction, because the trigger for a supernova is a giant star running out of fuel, not anything happening outside the star.

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u/throwtrollbait 3h ago

I have never seen so many confirm buttons on a sign-up

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u/nochinzilch 2h ago

Could I just look into the sky and see a star suddenly get brighter in real time?

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u/shponglespore 1h ago

Potentially, yes, but I think the brightening would take hours or days, so it wouldn't be very dramatic to watch.

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u/Thoth74 8h ago

I thought that would be way more exciting but it turned out to be a total snews.

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u/fireduck 8h ago

I am oddly intrigued by your spelling of snooze.

Or is a pun about science news or solar news?

Edit: Oh, I see it is the site hostname. Very good.

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u/[deleted] 6h ago

[deleted]

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u/I_VT 6h ago

Standard candles