The Sun’s radius is estimated to be 432,289 miles, but a growing number of researchers suspect this may be wrong and believe the Sun is actually larger. But is the Sun really bigger than we thought?
Xavier Jubier is one such eclipse enthusiast who has questions about the size of the sun. This rather creative man spent a lot of time providing very accurate simulations of solar and lunar eclipses, and he noticed that when a solar or lunar eclipse actually occurred, the moon’s position in front of the sun was often a little different than what his model predicted.
Upon examination, he concluded that the only explanation was that the sun’s radius must have increased by several hundred kilometers. If this is true, then why do astronomers make miscalculations about our own stars?
Currently, the value of 695,700 kilometers is defined by the International Astronomical Union (IAU), which itself was founded based on a 2008 study. As with the previous definition, the radius is measured reaching the edge of the photosphere, the visible envelope of light, the edge that we can see with the naked eye.
Due to the constant fluctuations and incredible brightness, this is a very difficult puzzle to measure accurately. This is not a solid dividing line, but a fluid one. Over time, photosphere measurements became more and more precise, but there was still a significant margin of error.
In fact, a 2008 IAU study put their precise figure at 695,658 kilometers, with an error of 140 kilometers. Jubier’s model shows values slightly larger than this, but no matter what, one thing is consistent: the sun is larger than we thought.
In fact, our sun is very, very small in the universe. It pales in comparison to UY Scuti, the largest star in the universe. The radius of this star is 2.13 billion kilometers, which is more than 3060 times that of our sun.