And this explains why the heavy elements are so neutron-rich! Astronomers just observed the collision of super-dense neutron stars for the first time. The collision caused gravity waves, confirming another one of Einstein's hypotheses. But it also produced heavy elements like the precious metals gold and platinum. Neutron stars are produced when stars form supernovae, but don't have enough mass to produce black holes. Instead, the star becomes an incredibly dense accumulation of neutrons with the mass of several suns, but the diameter of the city of Chicago. When neutron stars collide, new atoms and elements are formed.
'Then there were the observations of the debris. This picked up the presence of gold and other heavy elements in the debris, which again, clears up an outstanding mystery. Some heavy elements are readily formed in the environment created by a supernova, meaning it's easy to explain their abundance in the cosmos. But others can only form through pathways that involve the rapid ingestion of multiple neutrons—so fast that the atom doesn't have time to rearrange to accommodate the previous neutrons it had absorbed. Supernovae aren't thought to provide an environment that's sufficiently neutron-rich for this to occur.'
For more, read this article in Ars Technica.
'Then there were the observations of the debris. This picked up the presence of gold and other heavy elements in the debris, which again, clears up an outstanding mystery. Some heavy elements are readily formed in the environment created by a supernova, meaning it's easy to explain their abundance in the cosmos. But others can only form through pathways that involve the rapid ingestion of multiple neutrons—so fast that the atom doesn't have time to rearrange to accommodate the previous neutrons it had absorbed. Supernovae aren't thought to provide an environment that's sufficiently neutron-rich for this to occur.'
For more, read this article in Ars Technica.