Recent content by dtowne

Yes, heavy elements show up in supernova spectra all the time. Basically the first search result that I got was http://adsabs.harvard.edu/full/1956PASP...68..296B, and I know I've seen others. Whether or not those are stars that were initially "pure H and He" I don't know, but there's a...

Looks like the answer is in fact 1, as mentioned above. Rationale, from Wikipedia: "The creation of free neutrons by electron capture during the rapid collapse to high density of a supernova core along with quick assembly of some neutron-rich seed nuclei makes the r-process a primary...