Astronomers Find The Ancient Cosmic Event That Gave Earth Gold And Platinum

[beecee]

https://www.sciencealert.com/a-star-smash-up-billions-of-years-ago-rained-gold-and-platinum-on-the-solar-system

Astronomers Just Found The Ancient Cosmic Event That Gave Earth Gold And Platinum

MICHELLE STARR

8 MAY 2019

A violent collision between two neutron stars 4.6 billion years ago showered the as-yet-unformed Solar System with heavy elements, new research has found.

As much as 0.3 percent of Earth's gold, platinum and uranium (along with other heavy elements) could have been forged in the fire of a merger 1,000 light-years away, when the Solar System was little more than a cloud of gas and dust.

"This means that in each of us we would find an eyelash worth of these elements," said astrophysicist Imre Bartos of the University of Florida, "mostly in the form of iodine, which is essential to life."   

The famous neutron star collision detected in 2017 taught us many things - not least of which is that such collisions produce heavy elements. In the electromagnetic data produced by GW 170817, scientists detected, for the first time, the production of heavy elements including gold, platinum and uranium.

more at link.....

Edited May 9, 2019 by beecee

[et pet]

      See :  https://www.nature.com/articles/s41586-019-1113-7  ,  Nature 569, pages 85–88 (2019) 

   " A nearby neutron-star merger explains the actinide abundances in the early Solar System " Imre Bartos & Szabolcs Marka

     Abstract

   " A growing body of evidence indicates that binary neutron-star mergers are the primary origin of heavy elements produced exclusively through rapid neutron capture1,2,3,4 (the ‘r-process’). As neutron-star mergers occur infrequently, their deposition of radioactive isotopes into the pre-solar nebula could have been dominated by a few nearby events. Although short-lived r-process isotopes—with half-lives shorter than 100 million years—are no longer present in the Solar System, their abundances in the early Solar System are known because their daughter products were preserved in high-temperature condensates found in meteorites5. Here we report that abundances of short-lived r-process isotopes in the early Solar System point to their origin in neutron-star mergers, and indicate substantial deposition by a single nearby merger event. By comparing numerical simulations with the early Solar System abundance ratios of actinides produced exclusively through the r-process, we constrain the rate of occurrence of their Galactic production sites to within about 1−100 per million years. This is consistent with observational estimates of neutron-star merger rates6,7,8, but rules out supernovae and stellar sources. We further find that there was probably a single nearby merger that produced much of the curium and a substantial fraction of the plutonium present in the early Solar System. Such an event may have occurred about 300 parsecs away from the pre-solar nebula, approximately 80 million years before the formation of the Solar System. "

Edited May 9, 2019 by et pet

[swansont]

14 hours ago, beecee said:

 As much as 0.3 percent of Earth's gold, platinum and uranium (along with other heavy elements) could have been forged in the fire of a merger 1,000 light-years away, when the Solar System was little more than a cloud of gas and dust.

That's not really a lot.

Quote

"This means that in each of us we would find an eyelash worth of these elements," said astrophysicist Imre Bartos of the University of Florida, "mostly in the form of iodine, which is essential to life."   

Which means that most of this necessary Iodine came from somewhere else, and this particular merger was not a crucial event for us.

Seems to me they're trying to leverage the wrong thing to sensationalize the story.

 

[beecee]

9 hours ago, swansont said:

That's not really a lot.

Agreed, but we do know 5 billion years ago, that the universe was a far more violent place. The paper, which I missed putting in and kindly posted by et pet, does say "A growing body of evidence indicates that binary neutron-star mergers are the primary origin of heavy elements" and mentions "This is consistent with observational estimates of neutron-star merger rates" 

Quote

 

Which means that most of this necessary Iodine came from somewhere else, and this particular merger was not a crucial event for us.

Seems to me they're trying to leverage the wrong thing to sensationalize the story.

 

Certainly also I agree that many of these articles as per most journalism, will tend to sensationalize, which is why I include any associated scientific paper. In this case I forgot.

Edited May 10, 2019 by beecee

[et pet]

On 5/10/2019 at 8:12 AM, swansont said:

That's not really a lot.

Which means that most of this necessary Iodine came from somewhere else, and this particular merger was not a crucial event for us.

Seems to me they're trying to leverage the wrong thing to sensationalize the story.

 

  I agree, swansont, Three Tenths of One Percent is "not really a lot"!

  However, Pop-Science sites relying on a Revenue Stream often "leverage the wrong thing to sensationalize the story". 

  Click Bait, I believe some call it.

Edited May 11, 2019 by et pet

[et pet]

22 hours ago, beecee said:

Agreed, but we do know 5 billion years ago, that the universe was a far more violent place. The paper, which I missed putting in and kindly posted by et pet, does say "A growing body of evidence indicates that binary neutron-star mergers are the primary origin of heavy elements" and mentions "This is consistent with observational estimates of neutron-star merger rates" 

Certainly also I agree that many of these articles as per most journalism, will tend to sensationalize, which is why I include any associated scientific paper. In this case I forgot.

No.

The Paper : https://www.nature.com/articles/s41586-019-1113-7 ,  DOES NOT SAY "A growing body of evidence indicates that binary neutron-star mergers are the primary origin of heavy elements".

The Paper : https://www.nature.com/articles/s41586-019-1113-7 ,  SAYS  "A growing body of evidence indicates that binary neutron-star mergers are the primary origin of heavy elements produced exclusively through rapid neutron capture^1,2,3,4 (the ‘r-process’)."

  Yes, beecee, "most"of your Pop-Science Sites "will tend to sensationalize"!

However,  I do not find that to be true with "most journalism", as you put it, and I find that it is definitely not the case with Real Science Sites - such as  https://www.nature.com/ .

Edited May 11, 2019 by et pet

[beecee]

39 minutes ago, et pet said:

No.

The Paper : https://www.nature.com/articles/s41586-019-1113-7 ,  DOES NOT SAY "A growing body of evidence indicates that binary neutron-star mergers are the primary origin of heavy elements".

The Paper : https://www.nature.com/articles/s41586-019-1113-7 ,  SAYS  "A growing body of evidence indicates that binary neutron-star mergers are the primary origin of heavy elements produced exclusively through rapid neutron capture^1,2,3,4 (the ‘r-process’)." 

No problem et pet, and thanks again for posting the paper. 

Quote

Yes, beecee, "most"of your Pop-Science Sites "will tend to sensationalize"!

On occasions yes, which is why I normally include the paper.

Quote

However,  I do not find that to be true with "most journalism", as you put it, and I find that it is definitely not the case with Real Science Sites - such as  https://www.nature.com/ .

Perhaps not with nature, but "most" certainly do...seems to be a natural process with journalism. 

I would also add and I am sure you will agree, that the expertise on this forum in general, are always quick to highlight or dispute any wrong or false conclusion from any article and the journalism portrayed within. 

Edited May 11, 2019 by beecee

[beecee]

1 hour ago, et pet said:

"  Yes, beecee, "most"of your Pop-Science Sites "will tend to sensationalize"!

However,  I do not find that to be true with "most journalism", as you put it, and I find that it is definitely not the case with Real Science Sites - such as  https://www.nature.com/ .

Just to add though, obviously you seem to be comparing a basically science news site as is "physorg," with a science paper publishing company publishing peer reviewed articles as is "nature". I mostly include both as both give relevant outlines of the relevant news item I'm posting. Please take the time to read the many other articles and papers I post here in an effort to promote scientific discussion. 

 

Edited May 11, 2019 by beecee

[et pet]

3 hours ago, beecee said:

No problem et pet, and thanks again for posting the paper. 

On occasions yes, which is why I normally include the paper.

Perhaps not with nature, but "most" certainly do...seems to be a natural process with journalism. 

I would also add and I am sure you will agree, that the expertise on this forum in general, are always quick to highlight or dispute any wrong or false conclusion from any article and the journalism portrayed within. 

    Perhaps you may Cite evidence to support your statement : "Perhaps not with nature, but "most" certainly do...seems to be a natural process with journalism. "?

   Should be fairly easy, since "..."most" certainly do..." as you stated.

  And, No, I cannot agree "that the expertise on this forum in general, are always quick to highlight or dispute any wrong or false conclusion from any article and the journalism portrayed within. "

 

1 hour ago, beecee said:

Just to add though, obviously you seem to be comparing a basically science news site as is "physorg," with a science paper publishing company publishing peer reviewed articles as is "nature". I mostly include both as both give relevant outlines of the relevant news item I'm posting. Please take the time to read the many other articles and papers I post here in an effort to promote scientific discussion. 

 

Obviously?

I did not compare "a basically science news site as is "physorg," with a science paper publishing company publishing peer reviewed articles as is "nature" ".

I did not mention any "science news site ".

I did not even mention "physorg", and no "physorg" Links have been posted in this Thread.

I am not sure what you are trying to convey when you state : "I mostly include both as both give relevant outlines of the relevant news item I'm posting."

Maybe you could provide Links to your Posts where you "mostly include both as both give relevant outlines of the relevant news item I'm posting." ?

Edited May 11, 2019 by et pet

[beecee]

 

Here is another article with relation to heavier elements.....

 https://phys.org/news/2019-05-collapsar-accretion-disks-source-heaviest.html

Researchers suggest collapsar accretion disks might be source of heaviest elements: 

A trio of researchers at Columbia University is suggesting that collapsar accretion disks might be the major source of the heaviest elements. In their paper published in the journal Nature, Daniel Siegel, Jennifer Barnes and Brian Metzger describe their study of the accretion disks that form as neutron stars collapse into black holes, and what they found.

extract:

Prior research has suggested that the heaviest elements were created by what is known as the "r-process," in which a chain reaction results in atomic nuclei absorbing neutrons. Astrophysicists had theorized that two neutron stars colliding would likely give way to the conditions necessary for the r-process to occur, creating some of the heaviest elements. Two years ago, the team credited with observing the first gravity waves reported the effects of two neutron stars colliding. Subsequent study of the event showed that it was likely that the r-process had occurred, giving strong credence to the theory. But there was still one problem. The collision of neutron stars is a rare event—too rare to account for the amount of the heaviest elements that exist today. That led the researchers to consider other neutron star activities—such as their gravitational collapse.

more at link......

and the paper:

https://www.nature.com/articles/s41586-019-1136-0

<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

 

and an earlier  article from 2018 on the same process possibilities.....

https://physicstoday.scitation.org/doi/10.1063/PT.3.3815

extract:

 "The remainder of the chemical elements, except for a tiny amount of lithium, were forged in stellar interiors, supernova explosions, and neutron-star mergers. Elements up to and including iron are made in the hot cores of short-lived massive stars. There, nuclear fusion creates ever-heavier elements as it powers the star and causes it to shine. Elements heavier than iron—the majority of the periodic table—are primarily made in environments with free-neutron densities in excess of a million particles per cubic centimeter. The free neutrons, if captured onto a seed nucleus, result in a heavier, radioactive nucleus that subsequently decays into a stable heavy species. The so-called slow neutron-capture process, or s-process, mostly occurs during the late stages in the evolution of stars of 1–10 solar masses (M⊙). But the s-process accounts for the formation of only about half of the isotopes beyond iron. Creating the other half requires a rapid capture sequence, the r-process, and a density of greater than 1020 neutrons/cm3 that can bombard seed nuclei. The requisite neutron fluxes can be provided by supernova explosions (see the article by John Cowan and Friedrich-Karl Thielemann, Physics Today, October 2004, page 47) or by the mergers of binary neutron-star systems".

 

and relevant to Swansont's comment......

"Nuclear physicists are still working to model the r-process, and astrophysicists need to estimate the frequency of neutron-star mergers to assess whether r-process heavy-element production solely or at least significantly takes place in the merger environment."

the article then goes on to say.....

"To test r-process models, nuclear physicists will need to obtain measurements or solid predictions of the fundamental properties of heavy, unstable nuclei that lie far from the valley of stability occupied by familiar long-lived isotopes—they’ll need to know, for example, about masses, nuclear interaction cross sections, and decay rates. Procuring such data is a primary science driver for several international accelerator facilities. The US representative, the Facility for Rare Isotope Beams, is currently under construction at the campus of Michigan State University and is expected to be completed in 2022".

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Excellent article and far more informative then the latter article in the OP!!

 

Associated references from the above article....

https://science.sciencemag.org/content/358/6370/1570

Early spectra of the gravitational wave source GW170817: Evolution of a neutron star merger

https://science.sciencemag.org/content/358/6370/1574

Early spectra of the gravitational wave source GW170817: Evolution of a neutron star merger

https://iopscience.iop.org/article/10.1088/0004-637X/814/1/58/meta

MERGER RATES OF DOUBLE NEUTRON STARS AND STELLAR ORIGIN BLACK HOLES: THE IMPACT OF INITIAL CONDITIONS ON BINARY EVOLUTION PREDICTIONS

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Edited May 11, 2019 by beecee

[Strange]

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