Hot gases don’t produce a continuous emission spectrum. Black hydrogen absorption lines are at the same wavelength as the bright hydrogen emission lines. Key fact Line emission spectra are ...

This limitation has led to long-standing assumptions and uncertainties regarding the precise ratio of Helium to Hydrogen (He/H) in the Sun's surface layer.

Astrophysicists focused on the Sun as a model cool star to bridge this gap. For the first time, they successfully determined ...