A dark line in a spectrum that represents the absorption of energy at a particular wavelength of light. Each element on the periodic table absorbs energy at unique wavelengths. Astronomers identify which elements are present in an object, and other information about the object, by measuring these absorption lines. See also emission line spectral line
A line of finite width in the absorption spectrum. Absorption lines are characterized by their central wavelength, line intensity, and line width.
Dark narrow lines that represent absorption of energy at a particular wavelength of light. Each element on the periodic chart absorbs energy at specific wavelengths of light; this unique pattern looks like a bar code. See also: wavelength