|The Hertzsprung-Russell diagram developed by 2 astronomers in 1912,
plots some of the characteristics of a large number of stars. They
plotted spectral class vs. luminosity (brightness) of a large sample of
stars. Our Sun's luminosity is 3.9 x 1026 Joules/s. The plot spans a
large range in luminosity from a fraction of our Sun's brightness (0.01
times) to (10,000 times) much greater the strength of our Sun.