Lyman-alpha line
= Lyman-alpha line
{wiki=Lyman-alpha_line}
The Lyman-alpha line is a specific spectral line in the ultraviolet part of the electromagnetic spectrum. It corresponds to a transition of an electron in a hydrogen atom from the second energy level (n=2) to the first energy level (n=1). This transition emits a photon with a wavelength of approximately 121.6 nanometers (nm).