HOW BIG IS THE SUN?

          The sun is a large ball of gas. It is so large that, if it was hollow, one million Earth-sized planets could fit inside it! Sun is the largest and the most massive object in the solar system, but it is just a medium-sized star among the hundreds of billions of stars in the Milky Way galaxy.

          The sun is nearly a perfect sphere. Its equatorial diameter and its polar diameter differ by only 6.2 miles (10 km). The mean radius of the sun is 432,450 miles (696,000 kilometers), which makes its diameter about 864,938 miles (1.392 million km). You could line up 109 Earths across the face of the sun. The sun’s circumference is about 2,713,406 miles (4,366,813 km). It may be the biggest thing in this neighborhood, but the sun is just average compared to other stars. Betelgeuse, a red giant, is about 700 times bigger than the sun and about 14,000 times brighter.

          We have found stars that are 100 times bigger in diameter than our sun. “We have also seen stars that are just a tenth the size of our sun.” It’s possible that the sun is even larger than previously thought. Xavier Jubier, an engineer and solar eclipse researcher, creates detailed models of solar and lunar eclipses to determine precisely where the moon’s shadow would fall during the solar eclipse. But when he matched actual photos and historical observations with the models, he found precise eclipse shapes only made sense if he scaled up the sun’s radius by a few hundred kilometers.

          Even missions like NASA’s Solar Dynamics Observatory (SDO) and measurements of the inner planets across the face of the sun don’t refine the star’s radius as precisely as desired. “It’s harder than you think just to put a ruler on these images and figure out how big the sun is — [SDO] doesn’t have enough precision to nail this down,” NASA researcher Ernie Wright told Space. com. “Similarly, with the Mercury and Venus transits, it turns out [a measurement based on those is] not quite as precise as you’d like it to be.”

          Wright said different papers using a variety of methods have produced results that differ by as much as 930 miles (1,500 km). That could be a problem if you are planning to skirt the edges of the next solar eclipse.

          “For most people, yes, it doesn’t really matter; it won’t change everything,” Jubier said. “But the closer you get to the edge of the [eclipse] path, the more risk you take.”

Picture Credit : Google