This is a list of the largest optical telescopes in North America.
21st century A list of optical telescopes located in North America by aperture. Name Image Effective aperture m Aper. in Mirror type Nationality / Sponsors Site Built Large Binocular Telescope (LBT) 11.9 m (8.4 m×2) 330" × 2 Multiple mirror, 2 USA, Italy, Germany Mount Graham International Obs., Arizona, USA 2004W. M. Keck Observatory10m each394"Hexagonal Segments, 36 per telescopeUnited StatesMauna Kea Observatories1990,1993 Hobby–Eberly Telescope (HET) (11 m × 9.8 m mirror) 10 m 394" Segmented, 91 USA, Germany McDonald Observatory, Texas, USA 1997 Subaru (JNLT) 8.2 m 323" Single Japan Mauna Kea Observatories, Hawaii, USA 1999 MMT (1 x 6.5 M1) 6.5 m 256" Single USA F. L. Whipple Obs., Arizona, USA 2000 Hale Telescope (200 inch) 5.08 m 200" Single USA Palomar Observatory, California, USA 1948 MMT (6 × 1.8 m) original optics 4.7 m(6 × 1.8 m) 186" Segmented, 6 USA F. L. Whipple Obs., Arizona, USA 1979–1998 Lowell Discovery Telescope 4.3 m 169" Single USA Lowell Observatory, Happy Jack, Arizona 2012 Daniel K. Inouye Solar Telescope 4 m 158" Single USA Haleakala Observatory, Hawaii, USA 2019 Nicholas U. Mayall 4m 4 m 158" Single USA Kitt Peak National Obs., Arizona, USA 1973 USAF Starfire 3.5 m 3.5 m 138" Single USA Starfire Optical Range, New Mexico, USA 1994WIYN Telescope 3.5 m 138" Single USA Kitt Peak National Obs., Arizona, USA 1994Astrophysical Research Consortium (ARC) 3.48 m 137" Single USA Apache Point Obs., New Mexico, USA 1994 Shane Telescope 3.05 m 120" Single USA Lick Observatory, California, USA 1959 NASA-LMT retired 3 m 118" Liquid USA NASA Orbital Debris Obs., New Mexico, USA 1995–2002 For telescopes below 3 meters see List of large optical telescopes
Refractors Some of the big traditional refracting lens telescopes in North America: Name/Observatory Location Lens diameter Focal length Built Comments Image Yerkes Observatory Williams Bay, Wisconsin, USA 102 cm (40") 19.4 m (62′) 1897 Largest in operation James Lick telescopeLick Observatory Mount Hamilton, California, USA 91 cm (36") 17.6 m 1888 William Thaw Telescope Allegheny Observatory Pittsburgh, Pennsylvania, USA 76 cm (30") 14.1 m 1914 Brashear made, photographic Leander McCormick Observatory Charlottesville, Virginia, USA 66 cm (26") 9.9 m 1884 completed c. 1874, installed 1884 U.S. Naval Observatory Foggy Bottom Washington, DC, USA moved to Northwest, Washington, D.C., 1893 66 cm (26") 9.9 m 1873 Largest refractor in 1873. Alvan Clark & Sons mounting replaced with Warner & Swasey mounting in 1893. Sproul Observatory Pennsylvania, USA 61 cm (24") 11.0 m (36 ft) 1911 Currently under restoration to be re-installed in Northwest ArkansasLarge telescope moves to Northwest Arkansas to further STEM recruitment goals Lowell Observatory Arizona, USA 61 cm (24") 9.75 m (32 ft) 1894 Alvan Clark & Sons telescope
Biggest telescopes in 1950 Optical telescopes only
Name / Observatory Image Out Image In Aperture First Light Nation Hale TelescopePalomar Obs. 200 inch508 cm 1949 Hooker Telescope Mount Wilson Obs. 100 inch 254 cm 1917 McDonald Obs. 82 inchi.e. Otto Struve Telescope 82 inch 208 cm 1939 David Dunlap Observatory 74 inch 188 cm 1935 Plaskett telescope Dominion Astrophysical Obs. 72 inch 182 cm 1918 69-inch Perkins TelescopePerkins Observatory 69 inch 175 cm 1931–1964 Wyeth 61" reflectorOak Ridge Observatory 61 inch 155 cm 1933–2005 60 inch Hale Mount Wilson Observatory 60 inch 152.4 cm 1908
Biggest telescopes in 1900 Name/Observatory Aperture cm (in) Type Location then (Original Site) Extant* Yerkes Observatory 102 cm (40") achromat Williams Bay, Wisconsin, USA 1897James Lick telescope, Lick Observatory 91 cm (36") achromat Mount Hamilton, California, USA 1888 Crossley Reflector 91.4 cm(36") reflector – glass Lick Observatory, California, USA 1896 Harvard College Observatory 71 cm (28") reflector Cambridge, Massachusetts, USA 1889 McCormick Observatory 67 cm (26.37") achromat Charlottesville, Virginia, USA 1883U.S. Naval Observatory 66 cm (26") achromat Washington, DC, USA 1873 Lowell Observatory 61 cm (24") achromat Arizona, USA 1896 Halstead Observatory 58.4 cm (23") achromat Princeton, USA 1881 Chamberlin Observatory 50 cm (20") achromat Colorado, USA 1891 18½-in Dearborn Observatory Refractor 47 cm (18.5") achromat Chicago (1862–1893), Evanston, Illinois (1893), USA 1862 Flower Observatory 46 cm (18") achromat Philadelphia, USA 1896 Harvard Great Refractor, Harvard College Observatory 38 cm (15") achromat Cambridge, Massachusetts, USA 1847 Wellesley College Whitin Observatory 12-inch FitzJacob Campbell's 12 inch refractor 30 cm (12") achromat Massachusetts, USA New York, USA 19001852 University of Illinois Observatory 30 cm (12") achromat Urbana, Illinois, USA 1896 Merz und Mahler (Mitchell cupola), Cincinnati Observatory 28 cm (11") achromat Cincinnati, Ohio, USA 1843 Fraunhofer Refractor, United States Naval Observatory (Foggy Bottom) 24.4 cm (9.6") achromat Foggy Bottom, D.C., USA 1844Wesleyan University 6-inch Lerebours refractor 15.24 cm (6") achromat Connecticut, USA 1836Utzschneider & Fraunhofer Comet Seeker 10.2 cm (4") acrhomat Foggy Bottom, D.C., USA 1843
Biggest telescopes in 1850 Some of the largest at observatories: Name/Observatory Aperture cm (in) Type Location then (Original Site) Extant* Harvard Great Refractor, Harvard College Observatory 38 cm (15") achromat Cambridge, Massachusetts, USA 1847 Merz und Mahler (Mitchell cupola), Cincinnati Observatory 28 cm (11") achromat Cincinnati, Ohio, USA 1843West Point Observatory 9.75 inch Fitz equatorial 24.77 cm (9.75") achromat West Point, USA 1839 Fraunhofer Refractor, United States Naval Observatory (Foggy Bottom) 24.4 cm (9.6") achromat Foggy Bottom, D.C., USA 1844 Wesleyan University 6-inch Lerebours refractor 15.24 cm (6") achromat Connecticut, USA 1836 Yale Dollond 5-inch, Yale College Observatory 12.7 cm (5") achromat New Haven, Connecticut, USA 1828Utzschneider & Fraunhofer Comet Seeker 10.2 cm (4") acrhomat Foggy Bottom, D.C., USA 1843
See also Lists of telescopes List of radio telescopes List of largest optical reflecting telescopes (mirrors) List of largest optical refracting telescopes (lenses)
References
External links US Telescopes (1989)