BD+37 3172 is an orange K-type dwarf (about 3.75 solar masses, 4,500 K, 50.2 solar radii), 454 light-years from Earth. BD+37 3172 b is a 10.6-Jupiter-mass companion, with an orbital period of 5.17 years, at 4.650 AU from its star, on an eccentric orbit (e ≈ 0.59), discovered in 2023 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.