PX282 - G2 - internal structure

surface granulation

images: NST/BBSO

• the granulations on the solar surface are due to convection extending to about $30\mathrm{\%}$ of the radius into its interior
• this is known from the properties of helioseismology, which is the study of standing sound waves at the surface (pressure/p-modes) with a periodicity of about $5min$
• this is sensitive to the temperature profile, $T(r)$, and the rotation composition (pressure profile, $P(r)$, and density profile, $\rho (r)$)
• this gives numerical models of the solar interior, and the boundary between the convective and the radiative regions

images: k.r. lang, tufts university (left), carroll & ostile 2007 (right)

• the sun evolves to higher luminosity on the main sequence, which leads to the faint young sun paradox