Posted on 01/04/2020 8:50:56 PM PST by BenLurkin
Betelgeuse has gotten dramatically dimmer over the last few weeks, astronomers say the change probably isn’t a symptom of an impending stellar explosion.
That’s good news for any planets in the star’s orbit... But it’s disappointing news for Earth-based astronomers and stargazers, who haven’t been able to watch the death of a star with their unaided eyes since 1987, and may not have another chance for centuries.
In 1987, a supernova called SN 1987A, marked the death of a blue giant star in the Large Magellanic Cloud, one of the dwarf galaxies that orbits the Milky Way. 168,000 years after the star ran out of fuel and collapsed in on itself, the light of the resulting explosion reached Earth’s southern hemisphere – preceded a few hours earlier by a series of neutrino bursts.
(Excerpt) Read more at forbes.com ...
Now wait a second here. If nothing can go faster than light, then how did those neutrinos get here before the light did?
They took the express lane.
Wow, what was the FastTrack fee for that? Those little buggers must be loaded.
Because they carpool.
Pulses of neutrinos released before the “explosion” Just a guess I don’t know what kind of convulsions a collapsing star goes through. The electromagnetic spectrum is much more than visible light.
Along with the last light from before the star exploded.
There was a good episode back in the 70s...
Sorry.
Because they proceeded directly from the core at the moment of collapse, without getting absorbed or scattered by the outer layers of the star, without passing Go!, and without collecting $200. But photons are heavily scattered inside the star, and the expanding shock wave of pressure itself travels much slower than the speed of light, and has to reach the surface of the star before one sees it. (By which time the neutrinos are long gone.)
If you put a blasting cap inside the middle of a large sphere of explosive, you won’t see it the moment the cap goes off, but only when the shock makes it to the outside surface. But, supposing that blasting caps also made neutrinos (they don’t), the neutrinos would leave at the speed of light, and you’d see those first.
“preceded a few hours earlier by a series of neutrino bursts”
Aren’t neutrinos a kind of sable?
Ask Sulu. He’s not afraid of them.
Something that “May have” happened 650 years ago is now something that Greta “May” be concerned about now and I may be blamed for?
HOW DARE YOU!
[[Aren’t neutrinos a kind of sable?]]
You are thinking of a purina.
The article says they beat the light getting here.
The neutrinos are emitted right when the nuclear reactions go out of control in the core. The rest of the star is transparent to neutrinos so they escape immediately.
The light has to propagate through the mass of the body, most of which is opaque so it aborbs light and then reemits it. That takes time. In the sun I've seen estimates of thousands to millions of years for a photon to get from the core to the surface. During a supernova it takes less time because the driving force is the explosion's compression wave destroying the star which can take hours.
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