Moon is in circle shape , …

The sun is the most perfectly round natural object known in the universe, say scientists who have conducted precise measurements of its dimensions. As a spinning ball of gas, astronomers had always expected our nearest star to bulge slightly at its equator, making it very slightly flying-saucer shaped. To the eye, the moon appears round, and it's natural to assume that it is actually spherical in shape – with every point on its surface equidistant from its center – like a big ball. Not so. The shape of the moon is that of an oblate spheroid, meaning it has the shape of a ball that is slightly flattened. 

Stars are star-shaped because of imperfection in our eyes

Most stars are much like the Sun—giant balls of gas burning billions of miles away. These spherical stars pump out a steady stream of light that crosses vast stretches of space before it illuminates the night sky.