Home > Timeline of knowledge about galaxies, clusters of galaxies, and large-scale structure

• 964 - Al Sufi, a Persian astronomer makes the first preserved recording of the Large Magellanic Cloud.
• 1521 - Ferdinand Magellan observes the Magellanic Clouds during his circumnavigating expedition,
• 1610 - Galileo Galilei uses a telescope to determine that the bright band on the skyFor other uses, see Sky (disambiguation). The sky is often defined as the place a person sees when he or she looks up from the earth. Although almost everyone has seen it, the sky is hard to be defined precisely. The concept of the sky as it is applied he, the " Milky WayThis article is about the galaxy called the Milky Way. For the candy bar of the same name, see Milky Way candy bar. The Milky Way (a translation of the Latin Via Lactea in turn derived from the Greek Galaxia gala, galactos means "milk")) is a hazy band of", is composed of many faint starFor alternate meanings see star (disambiguation Hubble Space Telescope of the Sagittarius Star Cloud in the Milky Way Galaxy. A star is any massive gaseous celestial body in outer space. Stars appear as shining points in the nighttime sky that twinkle becs,
• 1750Events March 2 Small earthquake in London April 4 Small earthquake in Warrington, England August 23 Small earthquake in Spalding, England September 30 Small earthquake in Northampton, England November 16 Westminster Bridge officially opened Jonas Hanway i - Thomas WrightThomas Wright ( 1711 1786) was an English astronomer, mathematician, instrument maker, architect and garden designer. Wright is best known for his publication An original theory or new hypothesis of the universe (1750), in which he explains the appearance discusses galaxies and the shape of the Milky Way,
• 1755Events January 25 Moscow University established. July 9 French and Indian War: Braddock Expedition British troops and colonial militiamen are ambushed and suffer a devastating defeat inflicted by French and Indian forces. During the battle, British Genera - Drawing on Wright's work, Immanuel KantImmanuel Kant ( April 22, 1724 February 12, 1804) was a Prussian philosopher, generally regarded as the last major philosopher of the Enlightenment, having a major impact on the Romantic and Idealist philosophies of the 19th century, and as one of history conjectures that the galaxy is a rotating disk of stars held together by gravityThis article covers the physics of gravitation. See also gravity (disambiguation). Gravitation is the tendency of masses to move toward each other. The first mathematical formulation of the theory of gravitation was made by Sir Isaac Newton and proved ast, and that the nebulae are separate such galaxies,
• 1845 - Lord Rosse discovers a nebula with a distinct spiral shape
• 1918 - Harlow Shapley demonstrates that globular clusters are arranged in an spheroid or halo whose center is not the Earth, decides, correctly, that its center is the center of the galaxy,
• 1920 - Harlow Shapley 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,
• 1930 - Robert Trumpler uses open cluster observations to quantify the absorption of light by interstellar dust in the galactic plane; this absorption had plagued earlier models of the Milky Way,
• 1932 - Karl Guthe 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 Keenan Seyfert identifies six spiral galaxies with unusually broad emission lines, named Seyfert galaxies,
• 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 quasistellar object,
• 1962 - Cyril Hazard , M.B. Mackey, and A.J. Shimmins use lunar occultation s to determine a precise position for the quasar 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 - R. Brent Tully and Richard Fisher publish 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 Boötes 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" in the direction of Hydra and Centaurus,
• 1989 - Margaret Geller and John Huchra discover the " Great Wall", a sheet of galaxies more than 500 million light years long and 200 million wide, but only 15 million light years thick,
• 1990 - Michael Rowan-Robinson and Tom Broadhurst discover that the IRAS galaxy IRAS_F10214%2B4724 is the brightest known object in the Universe,
• 2004 - The European Southern Observatory discovers Abell 1835 IR1916, the most distant galaxy yet seen from Earth.

See also: Large-scale structure of the cosmos