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Alexander Nikolayevich Vyssotsky (Russian: Алекса́ндр Никола́евич Высо́тский, 23 May 1888 – December 31, 1973) was a Russian-American astronomer. Vyssotsky was born in Moscow, Imperial Russia, and received his master's degree from Moscow State University.
During his 35 years at the McCormick Observatory of the University of Virginia, United States he published many works. His best known is probably a catalog with five lists of stars entitled 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, characteristics. Until this time, most nearby stars had been identified by their large proper motions; however, not all stars close to the Sun have a large proper motion, and this selection criteria caused a bias in studies before the advent of Vyssotsky's catalogue. Vyssotsky's survey was carried out at McCormick Observatory using a 10-inch Cooke astrograph, donated by the Carnegie Institution of Washington and refigured by J. W. Fecker. It was used with an objective prism, which allowed spectra to be taken of all the stars in the field of view simultaneously. The spectra allowed Vyssotsky and others to classify the stars according to the surface temperature and gravity of the stars, and they identified thousands of dwarf M stars (which are intrinsically faint, and therefore had to be nearby if they were visible through the 10-inch).
In 1929, he married fellow astronomer Emma T. R. Williams, who was from Philadelphia. She was his lifelong scientific collaborator. They had one son Victor A. Vyssotsky (a mathematician and computer scientist) who was involved in Multics project and creator of Darwin computer game. Alexander Vyssotsky died in Winter Park, Florida.