The Michelson stellar interferometer is one of the earliest
astronomical interferometers built and used. The interferometer was proposed by
Albert A. Michelson
Albert Abraham Michelson FFRS HFRSE (surname pronunciation anglicized as "Michael-son", December 19, 1852 – May 9, 1931) was a German-born American physicist of Polish/Jewish origin, known for his work on measuring the speed of light and espe ...
in 1890, following a suggestion by
Hippolyte Fizeau.
The first such interferometer built was at the
Mount Wilson observatory
The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles.
The observ ...
, making use of its 100-inch (~250 centimeters) mirror. It was used to make the first-ever measurement of a stellar diameter, by Michelson and
Francis G. Pease
Francis Gladheim Pease (January 14, 1881 – February 7, 1938) was an American astronomer.
He joined the Yerkes Observatory in Wisconsin, where he was an observer and an optician. There he assisted George W. Ritchey who built many of America's f ...
, when the diameter of
Betelgeuse was measured in December 1920. The diameter was found to be 240 million miles (~380 million kilometers), about the size of the
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such a ...
of
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmos ...
, or about 300 times larger than the
Sun.
See also
*
History of astronomical interferometry
*
Fizeau interferometer
*
Michelson interferometer
The Michelson interferometer is a common configuration for optical interferometry and was invented by the 19/20th-century American physicist Albert Abraham Michelson. Using a beam splitter, a light source is split into two arms. Each of those ...
References
* Michelson, A. A., and Pease, F. G. (1921). ''Astrophys. J.'' 53, 249–259.
{{optics-stub
Observational astronomy
Interferometers