The Kepler 11145123 star, discovered in 2016, is the roundest natural object ever measured. Using asteroseismology, scientists were able to measure the oblateness of the star and found it’s even more perfectly spherical than the sun. – WTF Fun Facts
Source: Kepler 11145123 is Most Spherical Natural Object Ever Seen, Astronomers Say | Astronomy | Sci-News.com (sci-news.com)
Image credit: Mark A. Garlick