the art and science dealing with the use of a spectroscope, and the production and analysis of spectra; the action of using a spectroscope.
A technique used by astronomers that allows them to determine the properties, such as composition, temperature, and motion through space, of celestial objects by analyzing the spectra of celestial objects. For example, because each atomic element absorbs and emits light in a unique set of wavelengths, the astronomer can sift through the spectrum of a star and determine what elements are present in the star's atmosphere. From the shapes and depths of spectral lines, the astronomer can calculate fundamental qualities of a star, such as how fast the gases churn through the stellar atmosphere or the star's effective temperature. An astronomer may also be interested in correlations between the abundances of certain elements and the physical behavior of the star, the age of the star, or the abundances of other elements. For instance, compared with the Sun, stars with low amounts of iron are also low in almost every other element with respect to hydrogen. Spectroscopy is performed by astronomers with instruments called spectrographs.
The study of the characteristic frequencies of atoms or molecules by observing the radiation they emit or absorb.
study of spectra, especially experimental observation of optical spectra. It has been the basis of modern quantum physics, and provides an understanding of the interaction between electromagnetic radiation and matter.