Stellar Spectra and Atmospheric Composition

Abstract The distortions to the image and spectrum of a star being observed during occultation from a satellite are discussed. The primary distortions are shown to be due to refractive dispersion, small and large particle scattering, and absorption by various atmospheric gases. Representative stellar spectra in both the visible and ultraviolet are presented, and various features relating to specific atmospheric constituents are discussed. The possibility of recovering information concerning atmospheric composition from stellar spectra is considered and several distinct processes are used for illustration.