(a)[1]
State what the luminosity of a star means.
(b(i))[2]
A star in the constellation Canis Maior is $8.14 \times 10^{16}\,\text{m}$ from Earth and has luminosity $9.86 \times 10^{27}\,\text{W}$. Its surface temperature is $9830\,\text{K}$. Calculate the radiant flux intensity of the star’s radiation as seen from Earth. Include a unit in your answer.
(b(ii))[2]
Determine the radius of this star.
(c)[3]
Explain how the surface temperature of a distant star may be found from the wavelength spectrum of the star’s light.