HD 121504 is a Sun-like F-type star (about 1.62 solar masses, 6,027 K, 1.07 solar radii), 41.7 light-years from Earth. HD 121504 b is a 1.51-Jupiter-mass companion, with an orbital period of 63.3 days, at 0.330 AU from its star, discovered in 2003 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 121504 b orbits well inside Earth's distance from the Sun.