its it a thought that the very first stars were nearly totally made of Hydrogen and bigger than even Eta Corina with lifespans of only 100,000 years or so before they blew apart (litterally leaving nothing - not even blackholes).

10,000,000,000 minus 100,000 yrs leaves a very large number and plenty of time for more metal production.

Heard on NPR "stardate" that the above 1st gen. stars and the rare hyper-giants of today like Eta Carina leave no core to collapse - they totally blow apart in full.

I had never heard of that before - I had always thought that bigger = black hole after supernova all these years.