Stellar Atmospheres

In 1925, Cecilia Payne first applied the new science of quantum mechanics to the analysis of stellar spectra. Besides relating stellar spectral types to photospheric temperatures, Payne showed that stars - and hence most of the observable universe - are composed mostly of hydrogen. Today, SSP scientists and other astronomers analyze spectra to measure chemical abundances and other physical properties of stellar atmospheres. In addition to providing information on the structure and evolution of stars, these measurements constrain the ages and masses of the oldest stars in the galaxy.