I wrote: >Stellar fusion can account for the lighter elements up to and including iron, >but how the heavier elements arose is not so clear. Indeed, most of the >heavier
>elements might be produced by cold fusion processes. Well maybe most of the heavy elements can be explained by stellar fusion, but it seems the stellar origin of copper has been difficult to explain as this 2007 abstract attests: http://adsabs.harvard.edu/abs/2007astro.ph..3760R "Despite the many studies on stellar nucleosynthesis published so far, the scenario for the production of copper in stars remains elusive. In particular, it is still debated whether copper originates mostly in massive stars or in Type Ia supernovae. To answer this question, we compute self-consistent chemical evolution models taking into account the results of updated stellar nucleosynthesis. By contrasting copper evolution in ω Cen and the Milky Way, we end up with a picture where massive stars are the major factor responsible for the production of copper in ω Cen as well as the Galactic disc."
