Sun

Sun

Image courtesy of NASA / JPL-Caltec

Our own central star in the solar system, one of more than 100.000.000.000 stars in our Milky-Way galaxy. The Suns age is estimated to 4.500.000.000 years and it's only half way through a stars life-cycle.

The Sun shines due to the fusion of Hydrogen into Helium in it's core at an impressive 15.700.000 degrees Kelvin. The temperature cools to about 5.500 Celcius at the surface of the Sun, but only to rise again to 2.000.000 degrees in the outermost layer called Corona.

The Sun has a strong magnetic field which drives the formation of sunspots and flares, as well as the solar wind. The solar wind ejects solar particles into space and are trapped by the earths magnetic field which can be seen as northern light or aurora borealis.

Facts

Radius: 695.000km

Density: 1.409 g/cm3

Gravity: 274.0 m/s2

From Earth: 149.000.000km

Rotation: 25 Earth days

Surface temperature: 5.500 C

Core temperature: 15.000.000 C

Composition:

92.1% Hydrogen

7.8% Helium