Alexander Nikolayevich Vyssotsky (, 23 May 1888 – 31 December 1973) was a

Russian Russian(s) may refer to: *Russians (), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *A citizen of Russia *Russian language, the most widely spoken of the Slavic languages *''The Russians'', a b ...

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

. Born in

Moscow Moscow is the Capital city, capital and List of cities and towns in Russia by population, largest city of Russia, standing on the Moskva (river), Moskva River in Central Russia. It has a population estimated at over 13 million residents with ...

, in 1923 he moved to the United States, where he eventually became professor at the

University of Virginia The University of Virginia (UVA) is a Public university#United States, public research university in Charlottesville, Virginia, United States. It was founded in 1819 by Thomas Jefferson and contains his The Lawn, Academical Village, a World H ...

and vice-president of the

American Astronomical Society The American Astronomical Society (AAS, sometimes spoken as "double-A-S") is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC. The primary objective of the AAS is to promote the adv ...

. During his 35 years at the

McCormick Observatory The Leander McCormick Observatory is one of the astronomical observatories operated by the Department of Astronomy of the University of Virginia, and is situated just outside Charlottesville, Virginia (US) in Albemarle County on the summit of ...

of the

, he was sequentially promoted from instructor to assistant professor in 1928, and to professor in 1937. His best known work is probably a catalog with five lists of stars titled ''Dwarf M Stars Found Spectrophotometrically''. This work was important because it was the first list of nearby stars identified not by their motions in the sky, but by their intrinsic,

spectroscopic Spectroscopy is the field of study that measures and interprets electromagnetic spectra. In narrower contexts, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Spectrosc ...

, characteristics. Until this time, most nearby stars had been identified by their large

proper motions Proper motion is the astrometric measure of changes in the apparent places of stars or other celestial objects as they move relative to the center of mass of the Solar System. It is measured relative to the distant stars or a stable reference ...

; however, not all stars close to the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

have a large proper motion, and this selection criteria caused a

bias Bias is a disproportionate weight ''in favor of'' or ''against'' an idea or thing, usually in a way that is inaccurate, closed-minded, prejudicial, or unfair. Biases can be innate or learned. People may develop biases for or against an individ ...

in studies before the advent of Vyssotsky's catalogue. Vyssotsky's survey was carried out at McCormick Observatory using a 10-inch Cooke

astrograph An astrograph (or astrographic camera) is a telescope designed for the sole purpose of astrophotography. Astrographs are mostly used in wide-field astronomical surveys of the sky and for detection of objects such as asteroids, meteors, an ...

, donated by the

Carnegie Institution of Washington The Carnegie Institution for Science, also known as Carnegie Science and the Carnegie Institution of Washington, is an organization established to fund and perform scientific research in the United States. This institution is headquartered in W ...

and refigured by J. W. Fecker. It was used with an objective

prism PRISM is a code name for a program under which the United States National Security Agency (NSA) collects internet communications from various U.S. internet companies. The program is also known by the SIGAD . PRISM collects stored internet ...

, which allowed spectra to be taken of all the stars in the field of view simultaneously. The spectra allowed Vyssotsky and others to

classify Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...

the stars according to the surface

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

and

gravity In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

of the stars, and they identified thousands of

dwarf Dwarf, dwarfs or dwarves may refer to: Common uses *Dwarf (folklore), a supernatural being from Germanic folklore * Dwarf, a human or animal with dwarfism Arts, entertainment, and media Fictional entities * Dwarf (''Dungeons & Dragons''), a sh ...

M stars In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the r ...

(which are intrinsically faint, and therefore had to be nearby if they were visible through the 10-inch). Vyssotsky spent his youth in Moscow, Russia, where he worked in a major observatory. He served in the Russian army and took part in

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, where he used his knowledge of French, English and German to translate intercepted radio communications. After the

October Revolution The October Revolution, also known as the Great October Socialist Revolution (in Historiography in the Soviet Union, Soviet historiography), October coup, Bolshevik coup, or Bolshevik revolution, was the second of Russian Revolution, two r ...

he joined the anti-communist

White movement The White movement,. The old spelling was retained by the Whites to differentiate from the Reds. also known as the Whites, was one of the main factions of the Russian Civil War of 1917–1922. It was led mainly by the Right-wing politics, right- ...

, and after its defeat escaped to

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

and then to

Tunisia Tunisia, officially the Republic of Tunisia, is a country in the Maghreb region of North Africa. It is bordered by Algeria to the west and southwest, Libya to the southeast, and the Mediterranean Sea to the north and east. Tunisia also shares m ...

, where he worked as a science teacher. In 1923 he moved to the United States, where in 1929 he married a fellow astronomer

Emma Vyssotsky Emma Vyssotsky (October 23, 1894 – May 12, 1975, née Emma T. R. Williams) was an American astronomer who was honored with the Annie J. Cannon Award in Astronomy in 1946. Biography Emma earned her bachelor's degree in mathematics at Swarthmor ...

. She was his lifelong scientific collaborator. They had one son,

Victor A. Vyssotsky Victor Alexander Vyssotsky (February 26, 1931 – December 24, 2012) was a mathematician and computer scientist. He was the technical head of the Multics project at Bell Labs and later executive director of Research in the Information Systems Divi ...

, a

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

and

computer scientist A computer scientist is a scientist who specializes in the academic study of computer science. Computer scientists typically work on the theoretical side of computation. Although computer scientists can also focus their work and research on ...

who was involved in

Multics Multics ("MULTiplexed Information and Computing Service") is an influential early time-sharing operating system based on the concept of a single-level memory.Dennis M. Ritchie, "The Evolution of the Unix Time-sharing System", Communications of t ...

project and created the Darwin computer game.

References

External links

Articles by Vyssotsky
adsabs.harvard.edu {{DEFAULTSORT:Vyssotsky, Alexander N. 1888 births 1973 deaths American astronomers Russian astronomers Scientists from Moscow Moscow State University alumni University of Virginia faculty White Russian emigrants to the United States