A team of scientists have for the first time unambiguously measured the internal rotation of a Sun-like star and determined the inclination of its rotation axis. The results also prove that the body known to accompany the star is indeed an exoplanet and not - as previously argued - a small companion star called a brown dwarf. This is the first time that asteroseismology, the study of a star's internal oscillations, has been used to constrain the mass of an orbiting companion of a Sun-like star.