HD 188015 is a Sun-like G-type star (about 1.09 solar masses, 5,746 K), 50.7 light-years from Earth. HD 188015 b is a 1.50-Jupiter-mass companion, with an orbital period of 1.26 years, at 1.203 AU from its star, on an eccentric orbit (e ≈ 0.14), discovered in 2004 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.