This Star Is The Roundest Natural Object Ever Seen

"The new method that we propose in this paper to measure stellar shapes, asteroseismology, can be several orders of magnitude more precise than optical interferometry. It applies only to stars that oscillate in long-lived non-radial modes. The ultimate precision of the method is given by the precision on the measurement of the frequencies of the modes of oscillation. The longer the observation duration (four years in the case of Kepler), the better the precision on the mode frequencies. In the case of  KIC 11145123 the most precise mode frequencies can be determined to one part in 10,000,000. Hence the astonishing precision of asteroseismology."