THE fact that the so-called nebulium lines are found to be associated with hydrogen and helium lines only ... in all places of which there appear spectral lines of unknown origin or under ...

In 1925, grad student Cecilia Payne first proposed that stars were mostly made of hydrogen and helium and shaped our ...

Observations show that in some spectroscopic binaries, spectral lines from both stars are visible ... object in HD 34736 is a chemically peculiar helium-weak star with an effective temperature ...