INSIDE THE CORE
The solar core is the innermost part
of the Sun and the only region where
the conditions are extreme enough for
sustained nuclear fusion.
Temperatures reach roughly
15 million kelvin, while enormous
gravitational pressure compresses the
plasma to extremely high densities.
Under these conditions, hydrogen nuclei
can overcome their electrostatic
repulsion and participate in the
proton–proton chain reaction.
The result is the production of helium,
positrons, neutrinos and high-energy
photons.
The energy generated here ultimately
powers the Sun's light and heat.
THE MAIN ENERGY SOURCE
4H → He + ENERGY
Four hydrogen nuclei are ultimately
converted into one helium nucleus.
A small amount of mass is converted
into energy according to Einstein's
mass–energy equivalence.
CORE
RADIATIVE ZONE
CONVECTIVE ZONE
PHOTOSPHERE