How big is our Sun compared to other stars? In a dramatic and popular video featured on YouTube, the relative sizes of planets and stars are shown from smallest to largest. The above video starts with Earth’s Moon and progresses through increasingly larger planets in our Solar System. Next, the Sun is shown along as compared to many of the brighter stars in our neighborhood of the Milky Way Galaxy. Finally, some of the largest stars known spin into view. Note that the true sizes of most stars outside of the Sun and Betelgeuse are not known by direct observation, but rather inferred by measurements of their perceived brightness, temperature, and distance.
(Source of the text above: http://apod.nasa.gov/apod/ap130606.html )