The Hertzsprung-Russell (HR) diagram shows several star types. The luminosity of the Sun is L_⊙. [HR diagram image]
Identify, on the HR diagram, the position of the Sun. Label the position S.
[1]the fusion of hydrogen in the core eventually stops OR core contracts ✔ the hydrogen in a layer around the core will begin to fuse ✔ Sun expands AND the surface cools ✔ helium fusion begins in the core ✔ Sun becomes more luminous/brighter ✔
Suggest the conditions that will cause the Sun to become a red giant.
[2]electron degeneracy <
Outline why the Sun will maintain a constant radius after it becomes a white dwarf.
[1]«use of » \frac{R_\mathrm{D}}{R_\mathrm{G}}}=9 \times 10^{-6}
During its evolution, the Sun is likely to be a red giant of surface temperature 3000 K and luminosity 10^4 L_⊙. Later it is likely to be a white dwarf of surface temperature 10000 K and luminosity 10^-4 L_⊙. Calculate the (radius of the Sun as a white dwarf)/(radius of the Sun as a red giant).
[2]