A widely used, but now-obsolete, term for a young irregular variable; the modern name is classical T Tauri star (CTTS). The designation and its subgroups were based solely on the form of the light-curve, whereas the current system of classification also takes into account the presence of nebulosity, speed of variation, and spectral type. RW Aurigae itself is now classified as of type INT, with rapid variations and a T Tauri spectrum. See T Tauri star.