Metallicity
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In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal currently detectable matter in the universe is either hydrogen
The globular cluster M80. Stars in globular clusters are mainly older metal-poor members of population II.
Population I star Rigel with reflection nebula IC 2118
Sun
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The Sun is the star located at the centre of the Solar System. It is a massive sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surf
Metallicity
…is attributed to gas versus metals, or measuring the ratios of the number of atoms of two different elements as compared to the ratios found in the Sun. Stellar composition is often simply defined by the parameters X, Y, and Z. Here X represents the mass fraction of hydrogen, Y is the mass fraction of…
The Sun as viewed through a clear solar filter
The photosphere is structured by convection cells referred to as granules.
The Sun's transition region taken by Hinode's Solar Optical Telescope
During a total solar eclipse the solar corona can be seen with the naked eye.