Upcoming Supernova? | Nature News

[Oldman too]

This will be interesting to watch unfold.
https://www.nature.com/articles/d41586-022-00425-8

 

[berkeman]

Sorry for the question, but why will the Neutrinos arrive slightly before the light from the supernova?

 

[phinds]

Sorry for the question, but why will the Neutrinos arrive slightly before the light from the supernova?

Does seem backwards, doesn't it. Perhaps the mechanism of the supernova releases neutrinos before the visible explosion (implosion?) occurs?

 

[anorlunda]

Sorry for the question, but why will the Neutrinos arrive slightly before the light from the supernova?

The answer is in the text of the linked article.

Although the shock wave can take many hours to make it through the outer layers of the star and to become visible, neutrinos come out right away, practically at the speed of light. More than 99% of the energy from a core-collapse supernova escapes not as light, but as neutrinos.

Photons interact strongly with the ions and free electrons in the outer layers of the star, but neutrinos don't.

I recall reading previously that it can take years for em energy generated in our Sun's core to reach the surface.

 

[Vanadium 50]

why will the Neutrinos arrive slightly before the light from the supernova?

Neutrinos come at the start - the neutronization phase. Light, and for that matter, antineutrinos, come over a longer period as short-lived nuclei decay.