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How Long Has It Been Since We Saw A Supernova?
Forbes ^ | 12/31/2019 | Kiona N. Smith

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 ...


TOPICS: Astronomy; Science
KEYWORDS: astronomy; betelgeuse; catastrophism; science; sn1987a; supernova
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1 posted on 01/04/2020 8:50:56 PM PST by BenLurkin
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To: BenLurkin

Now wait a second here. If nothing can go faster than light, then how did those neutrinos get here before the light did?


2 posted on 01/04/2020 8:55:49 PM PST by ProtectOurFreedom
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To: ProtectOurFreedom

They took the express lane.


3 posted on 01/04/2020 8:57:17 PM PST by RandallFlagg (Fact: Gun control laws kill innocents.)
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To: RandallFlagg

Wow, what was the FastTrack fee for that? Those little buggers must be loaded.


4 posted on 01/04/2020 9:00:27 PM PST by ProtectOurFreedom
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To: RandallFlagg

Because they carpool.


5 posted on 01/04/2020 9:01:03 PM PST by Equine1952 ((You can die on your feet or live down on your knees. You can not do both. Freedom Is not Free))
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To: ProtectOurFreedom

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.


6 posted on 01/04/2020 9:03:12 PM PST by gundog ( Hail to the Chief, bitches!)
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To: ProtectOurFreedom

Along with the last light from before the star exploded.


7 posted on 01/04/2020 9:03:26 PM PST by BenLurkin (The above is not a statement of fact. It is either opinion or satire. Or both.)
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To: ProtectOurFreedom
They didn't. Neutrinos have almost no mass, so they travel extremely close to the speed of light.
8 posted on 01/04/2020 9:03:49 PM PST by Widget Jr
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To: BenLurkin

There was a good episode back in the 70s...

Sorry.


9 posted on 01/04/2020 9:04:41 PM PST by dp0622 (Radicals, racists Don't point fingers at me I'm a small town white boy Just tryin' to make ends meet)
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To: BenLurkin
?


10 posted on 01/04/2020 9:08:30 PM PST by Salamander (Living On The Ledge....)
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To: ProtectOurFreedom

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.


11 posted on 01/04/2020 9:09:35 PM PST by coloradan (The Enemy Media isn't chartered to inform but rather to advance the interests of certain elites.)
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To: ProtectOurFreedom
Now wait a second here. If nothing can go faster than light, then how did those neutrinos get here before the light did?

They were probably released by the dying star prior to the final explosion - presumably as part of its final death throes.
12 posted on 01/04/2020 9:10:35 PM PST by AnotherUnixGeek
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To: BenLurkin; Gamecock; SaveFerris

“preceded a few hours earlier by a series of neutrino bursts”

Aren’t neutrinos a kind of sable?


13 posted on 01/04/2020 9:15:09 PM PST by Larry Lucido
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Comment #14 Removed by Moderator

To: Salamander

15 posted on 01/04/2020 9:16:25 PM PST by Larry Lucido
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To: BenLurkin

Ask Sulu. He’s not afraid of them.


16 posted on 01/04/2020 9:16:35 PM PST by headstamp 2 (There's a stairway to heaven, but there's a highway to hell.)
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To: BenLurkin

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!


17 posted on 01/04/2020 9:17:08 PM PST by TexasTransplant (Damn the Torpedoes! Full Speed Ahead!)
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To: Larry Lucido

[[Aren’t neutrinos a kind of sable?]]

You are thinking of a purina.


18 posted on 01/04/2020 9:18:29 PM PST by headstamp 2 (There's a stairway to heaven, but there's a highway to hell.)
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To: Widget Jr

The article says they beat the light getting here.


19 posted on 01/04/2020 9:18:48 PM PST by ProtectOurFreedom
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To: ProtectOurFreedom
Now wait a second here. If nothing can go faster than light, then how did those neutrinos get here before the light did?

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.

In a supernova, why do we detect neutrinos before light?

20 posted on 01/04/2020 9:20:41 PM PST by KarlInOhio (Cutest internet video: Charlie bit my finger. Creepiest internet video: Joe Biden bit my finger.)
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