Alexander N. Vyssotsky
Encyclopedia
Alexander Nikolayevich Vyssotsky was an astronomer
. Vyssotsky was born in Moscow
, Russia
, and received his master degree from Moscow State University
.
During his 35 years at the McCormick Observatory
of the University of Virginia
, USA 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 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 life-long 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
.
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
. Vyssotsky was born in Moscow
Moscow
Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, and received his master degree from Moscow State University
Moscow State University
Lomonosov Moscow State University , previously known as Lomonosov University or MSU , is the largest university in Russia. Founded in 1755, it also claims to be one of the oldest university in Russia and to have the tallest educational building in the world. Its current rector is Viktor Sadovnichiy...
.
During his 35 years at the McCormick Observatory
McCormick Observatory
The McCormick Observatory is one of the astronomical observatories operated by the Department of Astronomy of the University of Virginia and is situated just outside of Charlottesville, Virginia in Albemarle County on the summit of Mount Jefferson . It is named for Leander J...
of the University of Virginia
University of Virginia
The University of Virginia is a public research university located in Charlottesville, Virginia, United States, founded by Thomas Jefferson...
, USA 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
Astronomical spectroscopy
Astronomical spectroscopy is the technique of spectroscopy used in astronomy. The object of study is the spectrum of electromagnetic radiation, including visible light, which radiates from stars and other celestial objects...
, characteristics. Until this time, most nearby stars had been identified by their large proper motions; however, not all stars close to the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
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
Astrograph
An astrograph is a telescope designed for the sole purpose of astrophotography. Astrographs are usually used in wide field surveys of the night sky as well as detection of objects such as asteroids, meteors, and comets.-Design:...
, donated by the Carnegie Institution of Washington and refigured by Fecker. It was used with an objective prism
Prism (optics)
In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use...
, which allowed spectra
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
to be taken of all the stars in the field of view simultaneously. The spectra allowed Vyssotsky and others to classify
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
the stars according to the surface temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
and gravity
Surface gravity
The surface gravity, g, of an astronomical or other object is the gravitational acceleration experienced at its surface. The surface gravity may be thought of as the acceleration due to gravity experienced by a hypothetical test particle which is very close to the object's surface and which, in...
of the stars, and they identified thousands of dwarf
Main sequence
The main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell...
M stars
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...
(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
Emma Vyssotsky
Emma Vyssotsky , born Emma T. R. Williams in Media, Pennsylvania was an American astronomer.-Biography:She received a Ph.D. in astronomy from Harvard College in 1930...
, who was from Philadelphia. She was his life-long scientific collaborator. They had one son Victor A. Vyssotsky
Victor A. Vyssotsky
Victor A. Vyssotsky, son of the astronomers Alexander N. Vyssotsky and Emma Vyssotsky is a mathematician and computer scientist. He was one of the team member of Multics project. Multics, whilst not particularly commercially successful in itself, directly inspired Ken Thompson to develop...
(a mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
and computer scientist
Computer scientist
A computer scientist is a scientist who has acquired knowledge of computer science, the study of the theoretical foundations of information and computation and their application in computer systems....
) who was involved in Multics
Multics
Multics was an influential early time-sharing operating system. The project was started in 1964 in Cambridge, Massachusetts...
project and creator of Darwin computer game. Alexander Vyssotsky died in Winter Park
Winter Park, Florida
Winter Park is a suburban city in Orange County, Florida, United States. The population was 24,090 at the 2000 census. According to the U.S. Census Bureau's 2006 estimates, the city had a population of 28,083. It is part of the Orlando–Kissimmee Metropolitan Statistical Area...
, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
.