Three stars—labeled A, B, and C—are observed. Their measured radii and surface temperatures are shown in the table.
Star | Radius (in solar radii R⊙) | Surface temperature (K)
A | 1.0 | 5800
B | 2.0 | 4100
C | 0.5 | 10000
(a) Rank the stars in order of increasing total power output (luminosity). Justify your ranking with quantitative reasoning.
(b) Calculate the luminosity of star B as a multiple of the luminosity of star A.
(c) Star C contracts while its surface temperature drops to 8000K. Determine the new radius (in solar radii) required for star C to radiate the same power it emitted initially.
(d) Discuss how the results illustrate the relative influence of radius versus temperature on a star’s luminosity.