User login

The Sun

Sun animation

The Sun is average star, but without its energy we would not exist.

It contains more than 99.8% of the total mass in the Solar System, with the planet Jupiter containing most of the rest. The Sun is primarily made up of hydrogen (75%) and helium (24%), together with small amounts of oxygen, carbon, neon and iron.

The Sun was born in a giant cloud of gas and dust, which collapsed under the force of its own gravity. As this material fell inwards it created a lot of heat and pressure. When the temperature in the middle, the Sun's core, reached about 1 million degrees it ignited causing it to begin nuclear fusion. When this happened, the Sun began producing its own light, heat, and energy. It takes about 50 million years for the Sun's energy to make its way from the core to the surface, and then another 8 minutes for the light to reach us here on Earth.

Astronomers have calculated that the Sun is about 4,500 million years old and should continue shining for another 5,000 million years or so before running out of fuel and undergoing a relatively peaceful death. The Sun is a very active place, as you can see from the SOHO animation (see right), and significant variations can be seen from day to day, and year to year. The activity arises from the bending and twisting of magnetic lines within the atmosphere of the Sun, which can lead to sunspots and solar flares.

Sun Data Sheet show »« hide
Facts and FiguresSun
Radius695,000 KM
Mass1.99 x 1030 kg or 332,830 Earths
Rotation Period25 Earth days at Equator
Surface gravity27.9 g
Surface Temperatureabout 5,500 °C
Core Temperatureabout 15,000,000 °C


Please note that over the weekend of the 26-28th May 2017 we will be switching over to our brand new website - during this time there may be periods where the site is difficult to access, and users will be unable to request observations from the telescope. Please bear with us during this time. All should be back up and running by the 29th May 2017.