Abundance distributions and origin of the elements

From the spectrum of a star we can obtain the abundance distribution of the elements. For most stars it agrees with that of the sun. Other stars show abundance anomalies connected with the origin of the elements. In an important group of stars the relative abundance of the heavier elements (briefly called metals) is the same as on the sun but their ratio to hydrogen, the so called metal abundance, varies considerably. Small metal abundance is found in the outer, a large one in the inner parts of our milky-way system and other galaxies. (orig.)