Nucleosynthesis
The CNO Cycle
A second route from hydrogen to helium, in which carbon, nitrogen, and oxygen act as catalysts that are used and regenerated. Because it is extremely temperature-sensitive, the CNO cycle dominates hydrogen burning in stars more massive than roughly 1.3 solar masses, whose cores are hotter than the Sun's.
Stars, stages & concepts
Knowledge connections
- Associated withMain-Sequence Evolution
- Associated withThe Proton–Proton Chain
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.