An Exploding Star 65 Light-Years Away From Earth May Have Triggered a Mass Extinction

[tecoyah]

Then explain the closest supernova remnant to Earth, the Lambda Orionis Ring (a.k.a. the Angelfish Nebula). Which, as I point out in post #7, is approximately one million years old and 1,100 light-years away.

A supernova is unique and does not follow specific guidelines to the T. Variations exists every time and the observations/expectations are general. Only Light is absolute and even that can be effected gravitationally.

 

[Glitch]

A supernova is unique and does not follow specific guidelines to the T. Variations exists every time and the observations/expectations are general. Only Light is absolute and even that can be effected gravitationally.

Supernovae are not unique, and they do follow physical laws that are both specific and predictable. Our observations of the supernova, because it does follow very specific physical laws, tell us a great deal about the progenitor star. Not just its mass at the times of its conflagration, but also its composition.

FYI, if light was absolute it would not be effected by gravity. Light can also be slowed to just one mile per hour by passing it through a Bose Einstein Condensate. Light is not absolute, you simply cannot have mass and achieve the speed of light.

 

[Glitch]

A million years is a far cry from 360 million years. I did say "typically". Here's a quote from another NASA link on SNR's.

" The third phase, the Snow-plow or Radiative phase, begins after the shell has cooled down to about 106 K. At this stage, electrons begin recombining with the heavier atoms (like oxygen) so the shell can more efficiently radiate energy. This, in turn, cools the shell faster, making it shrink and become more dense. The more the shell cools, the more atoms can recombine, creating a snowball effect. Because of this snowball effect, the SNR quickly develops a thin shell and radiates most of its energy away as optical light. The velocity now decreases as 1/r3. Outward expansion stops and the SNR starts to collapse under its own gravity. This lasts a few hundreds of thousands of years. After millions of years, the SNR will be absorbed into the interstellar medium due to Rayleigh-Taylor instabilities breaking material away from the SNR's outer shell. "

First, thanks for providing the link. It allowed me to find the original source for NASA's page:

The Interaction of Supernovae with the Interstellar Medium - Annual Review of Astronomy and Astrophysics, Volume 15, pp. 175-196, 1977.

The opening paragraph of that paper makes an excellent point. If there were a SNe, then there would be either a neutron star or, in the case of a core collapse SNe, a black hole left behind. The closest neutron star to Earth was found by NASA's Swift X-Ray telescope in 2007, somewhere between 250 and 1,000 light-years distant.

Astronomers Find Closest Neutron Star

X-ray telescope detects closest neutron star ever known.

www.space.com

We also just recently discovered in 2020 the closest black hole to Earth.

Newfound black hole is the closest one to Earth we've ever found

A newfound black hole may be the closest black hole to Earth, and you can spot its cosmic home in the night sky without a telescope.

www.space.com

Which is about 1,000 light-years distant. The next closest known black hole is 3,000 light-years away.

Even the smallest supernovae remnant leaves behind a neutron star. They also tend to stick around for a few billion, or in the case of black holes - trillions, of years.

 

[Glitch]

Addendum:

I'm compelled to point out that there is a third possibility for a SNe remnant other than a neutron star or black hole.

It is held by many astrophysicists that Type Iax SNe are only a partial conflagration of the progenitor star, leaving behind fragments of the degenerate white dwarf. Which would explain why the absolute magnitude of a Type Iax is between -14 and -18, and a Type Ia is -19 or brighter. It would also explains why the ejecta of a Type Iax is significantly slower than Type Ia SNe.

 

[Cordelier]

Then explain the closest supernova remnant to Earth, the Lambda Orionis Ring (a.k.a. the Angelfish Nebula). Which, as I point out in post #7, is approximately one million years old and 1,100 light-years away.

First, thanks for providing the link. It allowed me to find the original source for NASA's page:

The Interaction of Supernovae with the Interstellar Medium - Annual Review of Astronomy and Astrophysics, Volume 15, pp. 175-196, 1977.

The opening paragraph of that paper makes an excellent point. If there were a SNe, then there would be either a neutron star or, in the case of a core collapse SNe, a black hole left behind. The closest neutron star to Earth was found by NASA's Swift X-Ray telescope in 2007, somewhere between 250 and 1,000 light-years distant.

Astronomers Find Closest Neutron Star

X-ray telescope detects closest neutron star ever known.

www.space.com

We also just recently discovered in 2020 the closest black hole to Earth.

Newfound black hole is the closest one to Earth we've ever found

A newfound black hole may be the closest black hole to Earth, and you can spot its cosmic home in the night sky without a telescope.

www.space.com

Which is about 1,000 light-years distant. The next closest known black hole is 3,000 light-years away.

Even the smallest supernovae remnant leaves behind a neutron star. They also tend to stick around for a few billion, or in the case of black holes - trillions, of years.

Um, not quite. Neutron Stars only form from massive stars (>10 Solar Mass). Below that, you typically get a White Dwarf.

https://chandra.harvard.edu/blog/no...dwarfs are formed from,core of a massive star.

By my reckoning, there are 61 White Dwarf stars within 50 light years of Earth right now.

 

[phoenix2020]

We would. Evidence of a supernova would still remain even after 360 million years.

The sun completes a rotation around the galactic center roughly every ~225 million years. So, it's certainly possible for said supernova remnant to be some distance away now.

 

[Glitch]

Um, not quite. Neutron Stars only form from massive stars (>10 Solar Mass). Below that, you typically get a White Dwarf.

https://chandra.harvard.edu/blog/node/182#:~:text=White dwarfs are formed from,core of a massive star.

By my reckoning, there are 61 White Dwarf stars within 50 light years of Earth right now.

You obviously did not read Subrahmanyan Chandrasekhar's groundbreaking paper. If you had then you would know that the Chandrasekhar Limit for a white dwarf is 1.44 solar masses. Which means that if the star has less than three solar masses, it will end up a white dwarf upon death. A main sequence star that was between 3 and 10 solar masses will collapse into a neutron star. Only stars that exceed 10 solar masses will collapse into a black hole. The biggest supernovae are pair-instability supernovae and only occur when the star is between 130 and 250 solar masses. Which are exceptionally rare these days. Pair-instability supernovae leave behind nothing.

 

[Cordelier]

You obviously did not read Subrahmanyan Chandrasekhar's groundbreaking paper. If you had then you would know that the Chandrasekhar Limit for a white dwarf is 1.44 solar masses. Which means that if the star has less than three solar masses, it will end up a white dwarf upon death. A main sequence star that was between 3 and 10 solar masses will collapse into a neutron star. Only stars that exceed 10 solar masses will collapse into a black hole. The biggest supernovae are pair-instability supernovae and only occur when the star is between 130 and 250 solar masses. Which are exceptionally rare these days. Pair-instability supernovae leave behind nothing.

You may have read the paper, but you obviously didn't understand it. The Chandrasekhar Limit only applies to the stability of White Dwarf itself.... it has absolutely nothing to do with the stellar mass progenitor star that preceded it.

 

[joko104]

Nope....Much, much longer unless in light wavelength. Matter would probably be ejected at 10,000 mph or so.

Is the claim that it was radiation by matter?

 

[phoenix2020]

Is the claim that it was radiation by matter?

Cosmic rays e.g. predominantly single protons traveling at relativistic velocities.

 

[Cordelier]

The sun completes a rotation around the galactic center roughly every ~225 million years. So, it's certainly possible for said supernova remnant to be some distance away now.

Originally when you posted that, I figured the Sun and the (presumable) White Dwarf remnant would probably have roughly similar galactic orbits, but when I checked it out (using sample velocities of 45 White Dwarves within 65 LY of the Sun), I found out that their median radial velocity relative to the Sun was 15 km/s, or 5 x 10 (exp -6) c. Push that forward 360 million years, and it could possibly give a separation of 1800 LY. Of course, different bodies are on different trajectories, so that straight-line distance estimate is probably exaggerated... but even if you halve it, that's still probably 900 LY of additional separation... so good point!

 

[tecoyah]

Is the claim that it was radiation by matter?

Radiation is Light in this context.

 

[Cordelier]

The sun completes a rotation around the galactic center roughly every ~225 million years. So, it's certainly possible for said supernova remnant to be some distance away now.

I've got to correct my last post.... apparently I was off by a decimal place - 15 km/s is 5 x 10(Exp -5)c.... not 5 x 10(Exp -6)c (taking the speed of light at 299, 792 km/s). So the expected stellar drift over 360 million years would be about 18,000 ly at maximum, not the 1,800 ly that I posted. Always pays to double-check your work *L*.

 

[Mr Person]

Apparently according to some scientists global warming is not man made; it's coming from space and it may have contributed to killing life during the Late Devonian extinction. Exploding stars, Supernovas. Science is looking for iron-60, plutonium-244 and samarium-146 from that period in geographic layers.

An Exploding Star 65 Light-Years Away From Earth May Have Triggered a Mass Extinction

Is it that you didn't read what you linked, that you didn't understand what you read, or that you just had an urge to try to twist this into one of the most moronic AGW-denierist threads ever?

Nothing about the article says AGW is false. The article is about yet another entry in a line of theories about what might have caused rapid ozone depletion correlating with a die-offs: volcanism, asteroid impact, supernova (or other causes).

There is only one mention of "global warming": "In their new work, Fields and his team explore the possibility that the dramatic decline in ozone levels coinciding with the Late Devonian extinction might not have been a result of volcanism or an episode of global warming."

That in no way means "global warming is not man made", nor is "global warming" supposed to be a problematic result of ozone depletion. Ozone depletion might result from warming. But again, this is just a new competing theory about a possible cause of a die-off, not some kind of indictment of AGW.

​

Ozone depletion, gradual thinning of Earth’s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. The thinning is most pronounced in the polar regions, especially over Antarctica. Ozone depletion is a major environmental problem because it increases the amount of ultraviolet (UV) radiation that reaches Earth’s surface, which increases the rate of skin cancer, eye cataracts, and genetic and immune system damage.​

ozone depletion | Facts, Effects, & Solutions

Ozone depletion, gradual thinning of Earth’s ozone layer caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. The thinning is most pronounced in the polar regions, especially over Antarctica.

www.britannica.com

 

[Mr Person]

I knew we gave up on aerosol cans and Freon coolants too easily. The culprit may actually be stars blowing up millions of years ago and pummeling our atmosphere with cosmic radiation over thousands of years.

On a more serious note, it's an interesting hypothesis, though suffering from the causation vs. correlation issue. Hopefully they stay investigating especially if enough of those rare isotopes are found on earth.

Did you even read the article? It doesn't say that the cause of the modern ozone hole is or might be the result of a supernova.

Did you think about the article? The fact that a sufficiently close supernova might rapidly deplete atmospheric ozone in no way, shape, or form, means that release of CFCs does not ALSO deplete ozone. Nevermind that the the ozone depletion the theory refers to is global, not concentrated mainly over the Antarctic.



Then again, you did start this thread....

The joke of academic journals

During the lockdown I discovered Joe Rogan's podcast. I remember him from Newsradio back in the 90's and of course "Fear Factor". I perused his non-MMA and comedian catalog and found quite a few really interesting interviews. This is one of them. I've always been a bit of a cynic about peer...

debatepolitics.com

 

[calamity]

Supernovae is some powerful stuff, perhaps the universe's most powerful. So, with that in mind, 65 light years is really, really close. And, heaven help us if we are ever in the path of the gamma ray burst emitted by one of these nearby exploding stars.

 

[phoenix2020]

I'm not worried. Even the most aggressive, assertive guesses (and they are guesses) as to how these scenarios would unfold have them playing out over hundreds of years. It's not like we wake up one morning and the ozone layer is gone and we all cook. And for catastrophes over those time scales, we've proven to be a rather adaptable species.

 

[tecoyah]

I'm not worried. Even the most aggressive, assertive guesses (and they are guesses) as to how these scenarios would unfold have them playing out over hundreds of years. It's not like we wake up one morning and the ozone layer is gone and we all cook. And for catastrophes over those time scales, we've proven to be a rather adaptable species.

It is good to avoid pointless worry and the possibility of this scenario is so remote as to be non existent. That said the direct gamma burst would almost instantly cook our ozone layer off. We recently had a hit from a Magnetar that depleted it in minutes to an extent and then recovered.

 

[Underestimated]

Did you even read the article? It doesn't say that the cause of the modern ozone hole is or might be the result of a supernova.

Did you think about the article? The fact that a sufficiently close supernova might rapidly deplete atmospheric ozone in no way, shape, or form, means that release of CFCs does not ALSO deplete ozone. Nevermind that the the ozone depletion the theory refers to is global, not concentrated mainly over the Antarctic.



Then again, you did start this thread....

The joke of academic journals

During the lockdown I discovered Joe Rogan's podcast. I remember him from Newsradio back in the 90's and of course "Fear Factor". I perused his non-MMA and comedian catalog and found quite a few really interesting interviews. This is one of them. I've always been a bit of a cynic about peer...

debatepolitics.com

Did you miss the part where I stated, "On a more serious note..." I was being lighthearted and a little sarcastic about fluorocarbons and aerosols. Yes I read the article.