Additional Data:

Diameter:

1.392.684 km

Weight:

332.946 earth masses

Average distance to earth:

149.600.000 km

One Sun day lasts:

25 days

Density:

1.408 kg/m³

Gravitational accelleration:

274 m/s²

Temperature on the surface:

5.500 °C

Escape velocity:

617,6 km/s

Tilt of the rotational axis:

7,25 °

Composition:

92 % Hydrogen, 7,8 % Helium, 0,2 % further elements

Number of planets:

8

Number of dwarf-planets:

5

 

The sun is the closest star to earth. We are so close to her, that she outshines all other stars in the sky at daytime.

You should never look directly into the sun. It is dangerous and you could go blind.

The sun is the center of our planetary system, and her gravitational sphere of influence reaches up to one lightyear, right to the border of the Oort cloud. Her gravitational pull keeps planets, dwarf planets, asteroids and spaceships on their orbits. The sun itself is classified as a yellow dwarf star with a spectral class of G2 V. The sun was formed along with its planets from a collapsing gas and dust cloud over 4,57 billion years ago.

The sun holds today nealy the whole mass of the entire planetary system. She is by far the biggest celestial body in our vicinity with a diameter close to 100 times that of earth. The sun consists mainly of the elements hydrogen and helium. There are also traces of further elements. Since her formation the enormous mass of the sun enables her to do nuclear fusion. This process fuses two atoms of hydrogen under very high pressure and temperature together. It forms one atom of helium, heat and radiation. This radiation in the form of light takes 100.000 years to get to the surface of the sun. This light then needs for the rest of its journey to earth only eight more minutes.

The sun experiences a cycle of varying activity with an eleven-year period. At high activity chaotic mangetic field lines cause parts of the suns corona, its outer most gas shell, to be thrown away form it. These charged particals can cause heavy damage to satellites. But when the moon stands in front of the sun during an eclipse, then you can see the suns corona for a couple of minutes. The sun is now in the middle of her expected lifespan. She will shine for at least 4,5 billion more years.

The sun is presumably the first celestial body that lifeforms have recognized in the sky. Even very simple lifeforms have cycles that mimic day and night. Humans thought for a long time of the day with the sun and the night with the moon as a antagonism. Astronomical studies over generations led to the discovery that the sun is a star like all other stars that are visible in the night sky.

Circa 1200 BCT the first eclipse was written down.

Circa 200 BCT the greek mathematician and astronomer Aristarchos of Samos tried to calculate the distances to the sun and to the moon.

Solar spots were observed by astronomers for over two thousand years ago.

In 1610 Galileo Galilei observed the sun using a telescope for the first time.

In 1802 William Hyde Wollaston was able to detect absorption lines in the spectrum of the sunlight.

Only since the discovery of Einstein’s theorems we are able to explain the luminosity and the age of the sun.