The Sun is a star and it is the centre of our Solar System.
The Sun is the largest body in the Solar System as it is 1,392,000 kilometres across. That means that the Sun is more than one million times larger than Earth.
This star has a very important role for our system. The Sun keeps all the planets together, including the Earth. Because it is bigger than all the other planets in our solar system, the Sun generates a huge gravitational pull. This pull keeps all the planets in their orbital paths. Without the pull, the planets would simply float off into space.
Our Sun is not unique in the universe. It is a common middle-sized yellow star. There are trillions of other stars in the universe just like it. And as our Sun, many of these stars have their own systems of planets, moons, asteroids, and comets.
The Sun is mainly made of chemical elements. Astronomers who have studied its composition have found 67 of them, but the most common ones are and helium. The Sun is also formed by other elements, called metals. The most abundant metals are oxygen, carbon, neon and iron
The photosphere is the name given to the surface of the sun. The surface temperature of the sun is 5500 degrees centigrade, which is relatively cool when we consider that the core of the sun heats up to 15,000,000 degrees centigrade, as it burns to create energy!
But remember; never look directly at the Sun with a telescope or binoculars. It is extremely dangerous and it can cause you eye problems.
Check out this video from the Space School about the Sun! http://youtu.be/SsoGeq4XcCk