Solar interior · ~15 million K
The Solar Core
The innermost region of the Sun, out to about a quarter of its radius, where nuclear fusion powers the star. At roughly 15 million kelvin and immense density, hydrogen fuses to helium mainly through the proton–proton chain, releasing the energy that slowly works its way outward. Almost all of the Sun's luminosity is generated here.
Highlights
- ›Fusion powers the Sun here, at ~15 million K
The Sun, its layers & phenomena
Across solar physics
Knowledge connections
- Associated withThe Sun
- Associated withThe Radiative Zone
- Associated withThe Radiative Zone
- Associated withQuantum Tunneling
- Associated withMass–Energy Equivalence
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.