Figure 3-46 Iron in the Sun’s Atmosphere The upper ( absorption) spectrum is a portion of the Sun’s spectrum from 425 to 430 nm. Numerous dark spectral lines are visible. The lower (emission) spectrum is a corresponding portion of the spectrum of vaporized iron. Several emission lines can be seen against the black background. The iron lines coincide with some of the solar absorption lines, proving that there is some iron (albeit a very tiny amount) in the Sun’s atmosphere.