An astronomical discography

Increased telescopic power led to the realisation that many of the 'nebulae' have the form of thin discs viewed at various angles of projection, and later work demonstrated that these objects and our own Galaxy are constructed from individual stars, the orbits of the majority of which are nearly coplanar, and again we might suspect that this is a result of the mode of formation. Disc structure plays an important and often hidden role in many of the exotia actively studied by modern astrophysicists - in the processes that produce galaxies; in the formation of planets; in the birth of stars; in many binary stars, especially those containing white dwarfs, neutron stars or black holes; in active nuclei of galaxies, including quasars. Discs do not only occur but in most cases are responsible for remarkable observational properties