Overview
Classification
The Sun is classified as a yellow dwarf star. This means it is a smaller star, not too big and not tiny. The color yellow means that the Sun is not overly hot. Though still very hot, it is not as hot as other stars, like blue or white stars, nor as cold as red stars. This may sound not so great for our Sun, however it means that Earth is not roasted alive or freezing. Because the Sun is a yellow dwarf star that is the perfect distance from Earth, it provides life supporting light and heat to sustain a habitable temperature.
Size
When it comes to size, the Sun is huge compared to Earth. In fact, the Sun is 109 times the size of Earth, 1.3 million Earths can fit inside the Sun. That’s a lot of Earths! As you can see in the illustration below that tiny dot in the yellow is an almost to scale Earth. Note: I had to make Earth big enough to see.
Rotation
Much like the planets orbiting it, the Sun also spins around. At the equator, it takes 25 Earth days to rotate. While at its axis, one rotation of the Sun takes a little longer at 35 Earth days.
Structure
The Sun is made up of 91% hydrogen, 8.9% helium and .1% oxygen, carbon, neon, nitrogen, magnesium, iron, and silicone. Over all, the Sun makes up 99.8% of the solar system’s mass. The average temperature of the Sun is 27 million degrees Fahrenheit. That is really hot.
The Sun is structured differently than how the planets are, but there are some similarities. Like the planets, the Sun has a core. At its core the Sun is 27 million degrees F and is sustained by thermonuclear fusion. Thermonuclear fusion is caused when hydrogen atoms fuse with helium atoms and then the fusion releases a large amount of energy. This is why the Sun produces light and heat. The energy made is carried toward the surface by radiation into the radiative zone. The energy from the core bounces around in the radiative zone for a while. Then the energy escapes into the convective zone. This is where the temperature drops 3.5 million degrees. In the convective zone, plasma, a soup of ionized atoms, bubbles like boiling water. The surface of the Sun, which we can see, is 10,000 degrees Fahrenheit. Though it is cooler than the core, it can still make diamonds boil. Now that is hot! The surface of the Sun is 300 miles thick. This is not solid like Earth’s surface, but just an outer layer of gas. The tenuous chromosphere and the corona make up the thin solar atmosphere. Here is where sunspots and solar flares can be seen. Because the photosphere is so bright the light from the atmosphere can only be seen during solar eclipses. A solar eclipse happens when the moon passes between the Earth and the Sun. When visible, the chromosphere looks red, where the corona forms a beautiful white crown with shapes of plasma. The atmosphere temperature is as high as 3.5 million degrees F.
Fun Facts
Every 11 years the poles of the Sun shift magnet polarity. Magnetic polarity is like an electrical charge. When the Sun shifts polarity, the north pole will go from a positive charge to a negative charge. For the most part the Sun is calm, but when the polarity of the poles shift, the Sun is violent. The height of the Sun’s activity is called ‘Solar Maximum’. Solar weather can affect earth.
Sunspots are cooler dark features that are more circular in shape. They form when the Sun is at its maximum activity every 11 years.