HD 233604 is an orange K-type dwarf (about 1.50 solar masses, 4,791 K, 10.9 solar radii), 847 light-years from Earth. HD 233604 b is a 6.58-Jupiter-mass companion, with an orbital period of 192 days, at 0.747 AU from its star, discovered in 2013 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. HD 233604 b circles its star within the inner habitable zone.