News for hackers. Stuff that matters.

A comment on The periodic table, colour coded by the likely origin of each element. Parent comment

Re:The periodic table, colour coded by the likely origin of ... by Tuna-Fish on Tuesday August 11, 2020 @09:36AM (#24120108)
Two neutron stars merging is an extremely energetic event which emits vast amounts of degenerate neutron star material at speeds above escape velocity. Pretty much instantly after this material is liberated from the pressure and gravity of the neutron star, it starts decaying into normal matter, producing a vast menagerie of (generally very neutron-rich) elements, which then follow their decay chains until they end up as mostly stable elements.

Low-mass stars, like the Sun, will generally expand into many times their original size after hydrogen starts running out in their core. Much of these tenuous outer layers will be emitted during the final stages of the star, before the core collapses into a white dwarf.

[ Parent | on HN ]
Re:The periodic table, colour coded by the likely origin of ... by ninkendo on Tuesday August 11, 2020 @04:32PM (#24125630)
I've always wondered, does the presence of heavy elements on earth (ones which are likely to have formed via neutron star mergers) indicate that a pair of neutron stars merged relatively nearby our sun when it formed? Or is there just a diffuse amount of these elements in typical protostellar clouds all over the galaxy?

Perhaps a simpler way of asking: are the heavy elements we find on earth typical for an average planet? Or does a planetary system have to be "lucky" enough to have formed near a neutron star merger, for it to have elements like gold in measurable quantities?

[ Parent | on HN ]
Re:The periodic table, colour coded by the likely origin of ... by arethuza on Tuesday August 11, 2020 @09:51AM (#24120207)
"it starts decaying into normal matter"

Thanks - I had managed to miss the fact that being made in a neutron star collision implies that things like gold were once part of neutron stars.

I think this exceeds the coolness of having been in a supernova.

[ Parent | on HN ]
Re:The periodic table, colour coded by the likely origin of ... by ahazred8ta on Tuesday August 11, 2020 @09:52PM (#24127879)
The collision is messy and it splatters a huge amount of neutronium into space. This dissociates into a very hot mist of heavy elements, which eventually mixes into the surrounding nebula. The proto-solar disk was formed from this mixture.
[ Parent | on HN ]