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| "This is our star! This giant ball of burning gas is very far away, and very bright and hot. It's so big, that it would take hundreds of years to walk around the planet. It has a great gravitational pull that keeps all the other planets in check."
Our Sun is one of billions of stars in the known universe. It's just a huge ball of luminescent hydrogen, helium, and other gases, burning itself away for billions of years. It is classified as a main sequence G2 star on the H-R diagram (a chart commonly used for classification of stars). The outer layers of the Sun exhibit differential rotation: at the equator the surface rotates once every 25.4 days; near the poles it's as much as 36 days. This odd behavior is because the Sun is not a solid body like the Earth. Similar effects are seen in the gas planets. The differential rotation extends considerably down into the interior of the Sun, but core rotates as a solid body. Hydrogen inside the core is packed so tightly, and the temperature is so hot, that individual atoms ram into each other, forming heavier helium atoms and releasing energy in the process. This energy takes many thousands of years to make its way to the photosphere and out into space. |
