HD 168009 is a Sun-like G-type star (about 0.99 solar masses, 5,778 K, 1.21 solar radii), 23.3 light-years from Earth. HD 168009 b is a 9.5-Earth-mass planet, with an orbital period of 15.1 days, at 0.119 AU from its star, on an eccentric orbit (e ≈ 0.12), discovered in 2021 via radial velocity. The planet betrayed itself through the star's reflex motion — a technique that first revealed worlds around Sun-like stars in the 1990s and remains a workhorse of exoplanet discovery. The planet's marked eccentricity suggests past scattering events or perturbations from unseen companions.