The Chemical Composition of the Sun and Stars

French philosopher Auguste Comte (1798–1857), founder of positivism and of the science of sociology, wrote about astronomy in his 1835 book about the sciences: “We will never be able to determine the chemical composition of the stars, nor their density and temperature.” Only 25 years later German physicists Gustav Kirchhoff (1824–1887) and Robert Bunsen (1811–1899) discovered that by the analysis of the light of the sun and stars it is very well possible to determine of what substances these objects are composed. And nowadays also the densities and temperatures of stars and other celestial bodies can be determined with high accuracy.