The Mark III Stellar Interferometer was a long-baseline optical

astronomical interferometer An astronomical interferometer or telescope array is a set of separate telescopes, mirror segments, or radio telescope antenna (radio), antennas that work together as a single telescope to provide higher resolution images of astronomical objects ...

, located at the Mount Wilson Observatory,

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

.The Mark III stellar interferometer, M. Shao et al., ''Astronomy and Astrophysics'' 193, #1-2 (March 1988), pp. 357–371, . It had a maximum baseline of 32 meters and operated in wavelengths between 450 and 800 nm. A joint venture between the

United States Naval Observatory United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depo ...

, the

Naval Research Laboratory The United States Naval Research Laboratory (NRL) is the corporate research laboratory for the United States Navy and the United States Marine Corps. It was founded in 1923 and conducts basic scientific research, applied research, technological ...

, the

Smithsonian Astrophysical Observatory The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution, concentrating on astrophysical studies including galactic and extragalactic astronomy, cosmology, solar, earth and planetary sciences, the ...

, and the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

, it began operation in 1987 and was closed in 1992. The Naval Observatory later constructed a larger interferometer, the Navy Prototype Optical Interferometer.pp. 37–39, Overview of Multiple-Aperture Interferometry Binary Star Results from the Northern Hemisphere, Harold A. McAlister, pp. 35–44 in ''Binary Stars as Critical Tools and Tests in Contemporary Astrophysics, Proceedings of the 240th Symposium of the International Astronomical Union, Held in Prague, Czech Republic, August 22–25, 2006'', William I. Hartkopf, Edward F. Guinan, and Petr Harmanec, eds., pub. Cambridge University Press, 2006, ; . The Mark III interferometer was used to resolve a number of

spectroscopic binary A binary star is a system of two star, stars that are gravity, gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separa ...

system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment (systems), environment, is described by its boundaries, ...

s, including Alpha Andromedae, Phi Cygni, and many others.

References

{{reflist Interferometric telescopes 1987 establishments in California 1992 disestablishments in California