The Sun is exactly 1 AU from the earth. However it is not the biggest star. It's not the hottest star. How come it's the most visible to us? That's because it's just the closest to earth. Now think about this for a second. The Sun is the closest to earth yet it's 1 AU away. It's visible to us. Now think about everything else in the solar system. It's MORE than 1 AU away. My question is how many AU'S are all the planets away from earth?