GJ 1289 is a cool M-dwarf (about 0.21 solar masses, 3,296 K), 8.4 light-years from Earth. GJ 1289 b is a 6.3-Earth-mass planet, with an orbital period of 112 days, at 0.270 AU from its star, and an equilibrium temperature near 150 K, discovered in 2024 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. GJ 1289 b orbits well inside Earth's distance from the Sun.