The process that transfers energy from the Sun's core to its surface involves a combination of radiation and convection.
-
Nuclear Fusion in the Core: The Sun's core is where nuclear fusion occurs, generating energy through the fusion of hydrogen nuclei into helium. This process releases a tremendous amount of energy in the form of gamma-ray photons.
-
Radiative Zone: Outside the core is the radiative zone. Here, the energy produced in the core is transferred outward mainly through radiation. Photons emitted from the core are absorbed and re-emitted by particles in the radiative zone, a process that can take thousands to millions of years due to the dense plasma and the random paths that photons take.
-
Convective Zone: Once energy reaches the top of the radiative zone, it enters the convective zone. In this layer, heat is transferred by convection. Hot plasma rises toward the surface, cools as it reaches the top, and then sinks back down to be reheated in a continuous cycle. This movement creates convection cells that help transfer energy more efficiently toward the surface.
-
Photosphere: Finally, once the energy reaches the photosphere, it is emitted as sunlight. This is the visible surface of the Sun, from which energy is released into space.
In summary, energy moves from the core to the surface of the Sun through a combination of radiative transfer, in the radiative zone, and convective transfer, in the convective zone.