The Sun. The Sun formed between 4.5 and 5.0 billion years ago. It is a middle aged star for one of its size and type Our sun formed from gasses and materials left over from earlier generations of stars that first formed after the Big Bang. Some of the ancestor suns that gave us the material for our solar system may have been large, hot stars with short lifespans (measured in millions rather than billions of years), and many generations of such stars may have existed in our general area of the Milky Way before our sun formed. Our sun is a medium-sized yellow type G star. Type G stars are between 0.8 and 1.1 solar masses, they burn with surface temperatures between 5,000 and 5,800°C, and they contain various metals and ionized calcium.

1. Amara Graps of the Solar Center at Stanford explains that the sun is about 5.0 billion years old.
2. Suntrek’s page about the age of the sun.
3. A page about the sun with a fantastic collection of images of the sun.
4. The NASA Heliophysics web site.
5. An amazing SOHO spacecraft ultraviolet mpg video of the sun making one full revolution (over the course of about 21 Earth days).