Stellar Physics 5g: Iron Peak Fusion

Over view of late stage nuclear fusion in stars. This video covers:
- Fusion processes from Carbon to Iron.
- Carbon fusion
- Oxygen fusion
- Alpha process
- Summary of nuclear burning phases in stars.
- Importance of neutrino losses

[MrZackdaddy]

Fantastic! I was there to watch the process. It was, in a word, cool

[csgauss]

amazing video. i don't understand the few likes

[phdnk]

8:27
I asked about it the prev. video and now I came back with the answer.

Iron peak nuclei does not participate in thermonuclear fusion because of the photodisintegration of the possible products.
The background thermal radiation drives all nuclei on to the iron peak by destroying everything that does not fall in line, beginning from the weakest nuclei as temperature rises.
When its hot enough so that iron can be photodisintegrated -- oops happens because there is a lot of iron ready to go all at once,
if iron is degenerate than the core has some more time until it gets hot enough for neutronization.

It has been temperature all along what explodes the stars:
- it detonates the white dwarfs,
- it collapses iron cores (degenerate and non-degenerate)
- it causes pair instability.

The energy was willing, but the matter was weak.