The Sun is our star. It’s a star like many others in the Milky Way galaxy. As stars go, it’s on the smaller side. Classified as a Type G, or yellow dwarf star, the Sun has a surface temperature of about 10,000 degrees Fahrenheit. Seems like it’s VERY hot! But when you compare our Sun to the largest and hottest stars that have surface temperatures around 90,000 degrees Fahrenheit or more, the Sun seems relatively tame.
The Sun is made up of mostly hydrogen gas, with some helium and small amounts of heavier elements. The Sun creates the light and heat that we experience every day by burning hydrogen to produce helium. But how can the Sun burn hydrogen when there’s no air in space? The Sun burns hydrogen through a process called nuclear fusion. Under intense heat and pressure in the core of the Sun, hydrogen atoms merge to create an atom of helium, releasing light and heat at the same time. The Sun burns 600 million tons of hydrogen in its core every second. At that rate, the Sun will live about another 5 billion years before it runs out of fuel.
As the Sun begins to lose fuel near the end of its life, the surface of the Sun will swell up to consume Mercury, Venus and possibly the Earth as well. The Sun will cease to burn hydrogen, and the white-hot core will be left exposed to space. This core is known as a White Dwarf star. Our solar system will be enveloped in a beautiful nebula known as a planetary nebula. There are many planetary nebulae in the Milky Way that serve as examples of the fate of our own solar system.