Absorption Spectrum

Spectrum consisting of dark absorption lines superimposed over a continuum spectrum, created when a cooler gas absorbs photons from a hotter continuum source. The image shows the intricate dark Fraunhofer absorption lines superposed on the Sun’s background continuous spectrum.

Dark Fraunhofer absorption lines superposed on the Sun’s background continuous spectrum. Image source: http://s94958815.onlinehome.us/angryastronomer/sunspectrumnoao.jpg

Some or all content above used with permission from J. H. Wittke.