Sun Facts

There are about 100 billion stars in the Milky Way and our Sun is just one of them. As stars go it would be classed as a dwarf. It is composed of out 3/4 hydrogen, about 1/4 helium and small amounts of other elements.

The Sun has a diameter (ignoring the corona) of 1,400,000 km. that's about 107 x bigger than the Earth's and about 20 x bigger than Jupiter's.

The outside of the Sun is made up of three distinct regions

The Corona - Corona means crown. This is the outermost part of the Sun. It can only be seen directly during a total solar eclipse. Temperature up to 2 million degrees.

The Chromosphere - (2,500 km) Means coloured sphere. This is responsible for the absorption spectrum we will discuss later. Temperature up to 400,000 degrees.

The Photosphere - (450 km)

Means sphere of light. The visible surface of the Sun. Visible light from the Sun originates here. Temperature about 6,000 degrees.

The interior of the Sun is also three distinct regions

The Convective zone - (106,000 km) heat travels outwards by convection currents in the gas.

The Radiative zone - (420,000 km) heat travels outward by radiation. This zone becomes much denser as we move towards the middle.

The Core - (170,000 km) where nuclear fusion occurs producing energy. Temperature about 14 million degrees.