1The property of being metallic.

1. 1.1Astronomy The proportion of the material of a star or other celestial object that is in elements other than hydrogen or helium.
   count noun another study of these galaxies shows that they have very low metallicities

   Example sentencesExamples

   • Third, by examining its metallicity, we have determined that the Sun is a third-generation star made from several supernova episodes that enriched the local interstellar gas some 5 billion years ago.
   • However, independent information comes from extrasolar planet host metallicities, the supernova rate and the metallicity evolution of the Galaxy.
   • Scientists can look at stars all over the galaxy and determine the metallicity at the time they were formed.
   • The Sun's value of x, solar metallicity and Earth's biological time scale were used to help define the GHZ.
   • The ratio of heavier elements to hydrogen and helium is known as metallicity.