It is a member of the Milky Way galaxy . The Sun is a yellow dwarf star, which means it is a medium size star. It is believed to be over 4 billion years old. The Sun spins slowly on its axis as it revolves around the galaxy. The center, or core, of the Sun is very hot.
Nuclear fusion produces a lot of energy .
Some of this energy travels out into space as heat and light. Streams of gas particles known as the solar wind also flow out from the Sun. On the Sun's surface, we can see storms. The Sun also produces big explosions of energy called solar flares . These flares shoot fast moving particles off the Sun's surface.