The 2 3Π g , 3 3Π g , 4 3Σ g +, and 1 3Δ g states of the Na 2 molecule are observed by sub-Doppler Perturbation Facilitated Optical-Optical Double Resonance (PFOODR) spectroscopy. Absolute vibrational assignments and molecular constants are obtained for two of these states (3 3Π g , v = 0–25 observed, and 4 3Σ g +, v = 3–5, 13, 14 observed). Tentative vibrational assignments and provisional molecular constants are obtained for the 2 3Π g ( v = 43–89 observed) and 1 3Δ g ( v = 31–35, 40, 46–51 observed) states. Spin-orbit, spin-spin, and hyperfine splittings are observed. The direct 3Λ g + → a 3Σ u , 2 3Π g ∼ 3 3Π g perturbation-induced, and collision-induced contributions of these four 3Λ g states to the ubiquitous Na-vapor violet and ultraviolet emission bands are discussed.