4 ms·
The astrophysics here is not quite right. Stars actually do make elements heavier than iron (where else would they come from?), they just don't get any energy
by splat 13y ago
The astrophysics here is not quite right. Stars actually do make elements heavier than iron (where else would they come from?), they just don't get any energy out of them.
Also, it's a misconception that the iron on Earth is made in the cores of stars. That iron is almost all trapped in the resulting neutron star or black hole. The iron released to the rest of the universe is formed from the decay of nickel and cobalt in the supernova explosion.
- breadbox 13y agoIt's not only that they don't get any energy out of them (elements heavier than iron); they actually lose energy. Which means that splitting any elements heavier than iron that happen to be created will actually liberate energy. So yes, stars will temporarily make heavier elements, but surely not in any appreciable amount. Supernova explosions are where they generally come from.
- splat 13y agoThis is true. Although fusion into elements heavier than iron happens both during the last stages of a star's life and during the supernova itself, the last stages of the star's life last only a few hours anyway. At that point it really doesn't make too much sense to talk of a "star" since it's no longer in anything resembling equilibrium. It's more of an "event." Heavy elements fused deep in the star's core are likely to remain there during core collapse, and heavy elements fused in the shells or in the envelope during the explosion are likely to escape.
- vlasev 13y agoHere's a cool picture showing the layers of a star before collapse http://upload.wikimedia.org/wikipedia/commons/3/37/Evolved_star_fusion_shells.svg http://upload.wikimedia.org/wikipedia/commons/3/37/Evolved_s...
- aklemm 13y ago"The astrophysics here is not quite right," is my new favorite HN quote.