Here's why:
* Gravity: The Sun's immense gravity pulls its mass towards its center, creating a nearly perfectly spherical shape.
* Rotation: The Sun rotates, causing a slight bulge at its equator, making it slightly oblate (like a squashed sphere).
* Solar Flares and Eruptions: While these events are dramatic, they don't significantly alter the overall shape of the Sun.
So, while the Sun is incredibly round, it's not perfectly circular due to its rotation. However, the difference is very small and difficult to observe directly.
