HD 166724 is an orange K-type dwarf (about 0.81 solar masses, 5,127 K), 45.1 light-years from Earth. HD 166724 b is a 3.53-Jupiter-mass companion, with an orbital period of 14.1 years, at 5.420 AU from its star, on an eccentric orbit (e ≈ 0.73), discovered in 2012 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.