GJ 3021 is a Sun-like G-type star (about 0.90 solar masses, 5,540 K, 0.90 solar radii), 17.6 light-years from Earth. GJ 3021 b is a 3.37-Jupiter-mass companion, with an orbital period of 134 days, at 0.490 AU from its star, and an equilibrium temperature near 350 K, on an eccentric orbit (e ≈ 0.51), discovered in 2000 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.