Neutron Stars Creating Heavy Elements Using Fission

[Robert Zwilling]

Neutron Stars and Nuclear Fission
Scientists know that nuclear fusion is not just the primary source of energy for stars, but also the force that forges a variety of elements, the "heaviest" being iron.

The idea being that neutron stars create elements that are heavier than the heaviest elements in the periodic table, these massive short lived elements break down by fission but unlike regular fission they create elements like gold and uranium.

The picture of so-called nucleosynthesis for heavier elements like gold and uranium, however, has been somewhat more mysterious. Scientists suspect these valuable and rare heavy elements are created when two incredibly dense dead stars  —  neutron stars  —  collide and merge, creating an environment violent enough to forge elements that can't be created even in the most turbulent hearts of stars.

 

[Swank]

So the relatively large amount of gold on earth is owed entirely to a nearby and relatively rare neutron star collision?

 

[AllanR]

Some gold comes from dying low mass stars. Supernova - Wikipedia

 

[Robert Zwilling]

Here is star, J0931+0038, discovered in 1999, a distant red giant star, apparently created 700 million years after the big bang, with a good size collection of heavy elements. It is suspected that this star was created by the remnants of an earlier star, no dates yet, that also had heavy elements in it. It was supposed that stars could make heavy elements but not that early in the formation of the universe. Which could mean that the universe is older than we think, or we don't understand the physics of star formation directly after the big bang.

Recent analysis shows that it could contain an unusually high amount of midweight elements such as iron, nickel and zinc, and an "overabundance" of heavier elements like strontium and palladium. This is the first star so far to have large quantities of all these metal elements in it. Other stars have some of these heavier elements in them.

 

[THX1138]

Natural mineral formation on a planet is as complicated as life itself. Yes, we are all Star Stuff. But in a simplicity of an explosion, how does all of this come to be? Everything is very complex. Even a gold vein is complex. Very complex for just being Space Dust, and terrestrial thermal dynamics.

 

[Foxbat]

As far as I understand it, any element beyond Iron has to be created by Neutron Capture. This creates an unstable nucleus and the neutron soon converts to a proton (forming a new element) and emits a gamma photon.

Fusion can create elements up to and including Iron but much higher temperatures and pressures are needed to affect nutron capture and create heavier elements. This is why they are created in neutron stars and supernovae.

 

[Astro Pen]

Would I be right in surmising that the heaviest elements on earth, such as gold and uranium, exist in vast quantities near the centre of earths core?
It seems odd to me to imagine that the heavy stuff would stay near the surface while the earth was forming and very hot .

Update: Just done my homework. - Wow.

Core

Earth’s core is the very hot, very dense center of our planet.

education.nationalgeographic.org

 

[hitmouse]

As far as I understand it, any element beyond Iron has to be created by Neutron Capture. This creates an unstable nucleus and the neutron soon converts to a proton (forming a new element) and emits a gamma photon.

Fusion can create elements up to and including Iron but much higher temperatures and pressures are needed to affect nutron capture and create heavier elements. This is why they are created in neutron stars and supernovae.

Neutron capture, as done commercially for isotope manufacture, does not require particularly high temperature or pressure, just a good source of neutrons.

 

[Foxbat]

True. But the quantities produced commercially are tiny compared to stellar production. And what better source of neutrons than a neutron star?

Should add that before we started creating elements ourselves, it was all out of our hands so to speak. Except, perhaps for this place…

Natural nuclear fission reactor - Wikipedia

en.wikipedia.org

 

[Robert Zwilling]

Update: Just done my homework. - Wow.

Interesting article about the core. I knew the core stayed molten from radioactive energy but I didn't know the core was good for 95 billion years. The sun only has another 5 billion years. That would be like a car engine that couldn't fail for any reason for 10 million miles. A car engine like that would be passed along as a family heirloom for generations.