LSPM J2116+0234 is a cool M-dwarf (about 0.43 solar masses, 3,475 K, 0.43 solar radii), 17.6 light-years from Earth. LSPM J2116+0234 b is a 13.3-Earth-mass planet, with an orbital period of 14.4 days, at 0.088 AU from its star, on an eccentric orbit (e ≈ 0.18), discovered in 2019 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. The planet's marked eccentricity suggests past scattering events or perturbations from unseen companions.