10 Facts About the Sun

Ever want to know a bit more about the Earth’s closest star and primary source of energy for our climate system?

If so, have a look at these 10 interesting facts about the Sun:

1. Sunspots are cool areas on the visible surface of the Sun

Sunspot

They have a temperature of about 3000oC compared to the normal temperature of 6000oC

2. The spectrum of the Sun is crossed by fine dark lines

Sun-colour-spectrum

They are called Fraunhofer lines and are named after the German physycist who first studied them in detail.

3. The Sun’s fuel is hydrogen

3

It is changed into helium by nuclear fusion reactions which is the source of the heat and light of our star.

4. The Sun is about half way through its life

4

It is 4.5 billion years old and has enough hydrogen to continue for about another 5 billion years.

5. The Sun has a strong magnetic field which sometimes releases large quantities of charged particles into space as a solar flare

5

Solar flares can damage satellites orbiting the Earh and interfere with communications on the surface of our planet.

6. The Sun is a yellow dwarf star with a spectral class of G2V

6

When it’s hydrogen supply is used up, it will become a red giant star, engulfing Mercury, Venus and the Earth.

7. The Sun is just one of at least 100 billion stars in our Galaxy (the Milky Way)

7

It orbits at a distance of about 30,000 light-years from the centre of the Galaxy and takes about 250 million years to complete one orbit.

8. The visible surface of the Sun is called the photosphere and its ‘atmosphere’ is called the corona

8

The corona can be seen at the time of a total solar eclipse.

9. Ancient civilisations believed that the Sun orbited the Earth

9

It wasn’t until the 17th centuy that it became widely accepted that the Sun was effectively at the centre of the Solar System.

10. The Sun is rotating

rotating Sun animated gif.

  Its equator rotates about once every 26 days but the poles rotate more slowly, taking 30 days.

Taught science for 16 years at a secondary school in the East Midlands.