On a clear day, we see that the sun always rises in the east and sets in the west, which is actually a reflection of the earth's rotation from west to east, which is astronomically called the sun's perihelion motion. The sun also rotates, but the speed of rotation is not the same between the latitudes of the sun's surface, which indicates that the sun is not solid. The Sun carries the various bodies in our solar system around the center of the Milky Way at a speed of 250 kilometers per second, which is the Sun's rotational motion. One week of rotation is about 250 million years.