What is the only known perfectly round natural object in the universe?

Answer:Sun

Explanation:

Sun is considered to be the Perfectly round natural object in the universe.

The bulging effect in sun is almost zero i. e. the difference in its diameter at Poles and equator is only 10 km which proves that the sun is the most spherical object in the universe. Bulging effect is seen at equators i. e. slightly saucer-shaped due to the high spin of Stars or Planet but this effect is almost nil in sun.