We think of the Sun as that bright ball of gas that travels across our sky each day. The Sun is a typical star, of average size and temperature. Many stars are much bigger and hotter, and many stars are smaller and cooler. There are billions of stars in the universe like our Sun. It is special in only one way, it is our Sun.
The Sun is our source of heat, light and energy, without it we could not exist. The nature of the Sun, its past and future, are vital to our continuing survival. A small variation in the energy output of the Sun could drastically affect our lives.
The diameter of the Sun is about 1.4 million km across. It has an average surface temperature of 5800K. At its equator, the Sun turns once every 25 days. Because the Sun is a large gaseous body, it spins at different rates at different places. The Sun is somewhat flattened, the poles spin fastest and the equatorial regions are slowest.
Copyright © 1997 Kathy A. Miles and Charles F. Peters II