In astronomy an pheesical cosmology, the metallicity or Z is the fraction o mass o a starn or ither kind o astronomical object that isna in hydrogen (X) or helium (Y).[1][2]

The globular cluster M80. Starns in globular clusters are mainly aulder metal-puir members o Population II.


  1. D. Kunth & G. Östlin (2000). "The Most Metal-poor Galaxies". 10 (1). The Astronomy and Astrophysics Review. Retrieved 3 Februar 2015. Cite uses deprecated parameter |last-author-amp= (help); Cite journal requires |journal= (help)
  2. W. Sutherland (26 Mairch 2013). "The Galaxy. Chapter 4. Galactic Chemical Evolution" (PDF). Archived frae the original (PDF) on 26 Januar 2020. Retrieved 13 Januar 2015.