99% of the energy from a core-collapse supernova comes out as neutrinos! They "freeze" the core, helping it implode, then heat the shock wave that blows the rest of the star to bits. All in 10 seconds. neutrinos.fnal.gov/sources/supern
Conversation
Replying to
Fun supernova fact; if you’re a within a few AU of a supernova, the neutrinos alone will kill you. Even if you’re inside a hundred miles of lead shielding. Or hiding behind an entire planet.
6
8
31
I thought - mistakenly it appears - that neutrinos pass through matter without interacting with it. How do they kill you?
2
2
~70 trillion solar neutrinos hit your hand per second. They have a **really** small probability of interacting with the matter in your hand, but it's not exactly zero. Take that 70 trillion and MULTIPLY it by a quadrillion! That's the difference between the sun and a supernova.
2
6
Also - though I’m not an expert - I think the very high energy neutrinos made in a core collapse have a higher chance of interacting than lazy solar neutrinos. (That’s why they can deposit energy in the rest of the star)
2
4
Yep: CCSN neutrinos are a little more than 10x more energetic than solar neutrinos (on average) --> 100x the chance to interact! But, it's the flux that's gonna get ya.
1
3
So, are there any stars in our “neighbourhood” that could potentially present a danger due to supernova neutrino flux density? Maybe not for billions of years, of course.
1
1
Betelgeuse is--by far--the closest likely suspect. Neutrino detectors around the globe will have A LOT of data when it goes off, but we'll be quite safe from the neutrinos: something like a small fraction of a medical x-ray.
2
3
I had an astrophysics class do this as an exercise and we came up with 2 AU as a lethal radius - so not a big deal. Though this required assuming the lethal dose in grays absorbed by your body is the same for absorbed neutrinos as gamma rays
1
3
If you are within 2AU of a supernova the neutrinos are the least of your worries.
2
3
No, but they are probably your first.