GJ 433 is a cool M-dwarf (about 0.48 solar masses, 3,461 K), 9.1 light-years from Earth. GJ 433 b is a 6.0-Earth-mass planet, with an orbital period of 7.4 days, at 0.062 AU from its star, discovered in 2013 via radial velocity. GJ 433 d is a 5.2-Earth-mass planet, with an orbital period of 36.1 days, at 0.178 AU from its star, on an eccentric orbit (e ≈ 0.07), discovered in 2020 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.