### Question --- What are HH objects? T Tauri stars? Bipolar flows? OH masers? Where are they all found? ### Answer --- Below, there is more details about each object. All are formed or observed in star forming regions, and some in [[Hertzsprung-Russell Diagram#Post-Asymptotic Giant Branch (Post-AGB)|post-AGB]] stars. ![[Stellar Classes#Herbig–Haro (HH) Objects]] ![[Stellar Classes#T Tauri Stars]] ![[Stellar Classes#Bipolar Flows]] ![[Stellar Classes#OH Maser]]