Chronology of Galaxies, Clusters of Galaxies, and Large Scale Structure

1521	Ferdinand Magellan observes the Magellanic Clouds during his circumnavigating expedition.
1750	Thomas Wright discusses galaxies and the shape of the Milky Way.
1845	Lord Rosse discovers a nebula with a distinct spiral shape.
1918	Harlow Shapley demonstrates that globular clusters surround our galaxy like a halo and are not centered on the Earth.
1920	Harlow Shapely and Heber Curtis debate whether or not the spiral nebulae lie within the Milky Way.
1923	Edwin Hubble resolves the Shapely-Curtis debate by finding Cepheids in Andromeda.
1932	Karl Jansky discovers radio noise from the center of the Milky Way.
1933	Fritz Zwicky applies the virial theorem to the Coma cluster and obtains evidence for unseen mass.
1936	Edwin Hubble introduces the spiral, barred spiral, elliptical, and irregular galaxy classifications.
1939	Grote Reber discovers the radio source Cygnus A.
1943	Carl Seyfert identifies six spiral galaxies with unusually broad emission lines.
1949	J.G. Bolton, G.J. Stanley, and O.B. Slee identify NGC 4486 (M87) and NGC 5128 as extragalactic radio sources.
1953	Gerard de Vaucouleurs discovers that the galaxies within approximately 200 million light years of the Virgo cluster are confined to a giant supercluster disk.
1954	Walter Baade and Rudolph Minkowski identify the extragalactic optical counterpart of the radio source Cygnus A.
1960	Thomas Matthews determines the radio position of 3C48 to within 5''.
1960	Allan Sandage optically studies 3C48 and observes an unusual blue quasi stellar object.
1962	Cyril Hazard, M.B. Mackey, and A.J. Shimmins use lunar occultations to determine a precise position for 3C273 and deduce that it is a double source.
1963	Maarten Schmidt identifies the redshifted Balmer lines from the quasar 3C273.
1973	Jeremiah Ostriker and James Peebles discover that the amount of visible matter in the disks of typical spiral galaxies is not enough for Newtonian gravitation to keep the disks from flying apart or drastically changing shape.
1974	B.L. Fanaroff and J.M. Riley distinguish between edge-darkened (FR I) and edge-brightened (FR II) radio sources.
1976	Sandra Faber and Robert Jackson discover the Faber-Jackson relation between the luminosity of an elliptical galaxy and the velocity dispersion in its center.
1977	Brent Tully and Richard Fisher discover the Tully-Fisher relation between the luminosity of an isolated spiral galaxy and the velocity of the flat part of its rotation curve.
1978	Steve Gregory and Laird Thompson describe the Coma supercluster.
1978	Vera Rubin, Kent Ford, N. Thonnard, and Albert Bosma measure the rotation curves of several spiral galaxies and find significant deviations from what is predicted by the Newtonian gravitation of visible stars.
1981	Robert Kirshner, August Oemler, Paul Schechter, and Stephen Shectman find evidence for a giant void in Bootes with a diameter of approximately 100 million light years.
1985	Robert Antonucci and J. Miller discover that the Seyfert II galaxy NGC 1068 has broad lines which can only be seen in polarized reflected light.
1986	Amos Yahil, David Walker, and Michael Rowan-Robinson find that the direction of the IRAS galaxy density dipole agrees with the direction of the cosmic microwave background temperature dipole.
1987	David Burstein, Roger Davies, Alan Dressler, Sandra Faber, Donald Lynden-Bell, R.J. Terlevich, and Gary Wegner claim that a large group of galaxies within about 200 million light years of the Milky Way are moving together towards "The Great Attractor''.
1990	Michael Rowan-Robinson and Tom Broadhurst discover that the IRAS galaxy F10214+4724 is the brightest known object in the universe.