Astrophysical jet

A polar jet is a phenomenon often seen in astronomy. It is usually caused by the dynamical interactions within an accretion disc. The largest polar jets are those seen in active galactic nuclei such as quasars. Other systems which often contain polar jets include cataclysmic variables, X-ray binaries and T Tauri stars. Herbig-Haro objects are caused by the interaction of polar jets with the interstellar medium.