Mary Ross Calvert (June 20, 1884 – June 25, 1974) was an American astronomical

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

and

astrophotographer Astrophotography, also known as astronomical imaging, is the photography or imaging of astronomical objects, celestial events, or areas of the night sky. The first photograph of an astronomical object (the Moon) was taken in 1840, but it was no ...

. She started as her uncle

Edward Emerson Barnard Edward Emerson Barnard (December 16, 1857 – February 6, 1923) was an American astronomer. He was commonly known as E. E. Barnard, and was recognized as a gifted observational astronomer. He is best known for his discovery of the high proper mo ...

's assistant and ended publishing his (and their) work that cataloged over 300 dark objects (

dark nebula A dark nebula or absorption nebula is a type of interstellar cloud, particularly molecular clouds, that is so dense that it obscures the visible wavelengths of light from objects behind it, such as background stars and emission or reflection nebu ...

e) — primarily those that

extinguish A fire extinguisher is a handheld active fire protection device usually filled with a dry or wet chemical used to extinguish or control small fires, often in emergencies. It is not intended for use on an out-of-control fire, such as one which ha ...

the most starlight reaching the earth lie between the bulk (inward local sector, central bulge, and other sectors of the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

) thus between the Local Arm (Orion Arm) and the

Sagittarius Arm Sagittarius ( ) may refer to: *Sagittarius (constellation) *Sagittarius (astrology), a sign of the Zodiac Ships *'' SuperStar Sagittarius'', a cruise ship * USS ''Sagittarius'' (AKN-2), a World War II US Navy cargo ship Music *Sagittarius (ba ...

. She went on to publish other photographic works on astronomy.

Early life

Calvert was born in

Nashville, Tennessee Nashville is the capital city of the U.S. state of Tennessee and the county seat, seat of Davidson County, Tennessee, Davidson County. With a population of 689,447 at the 2020 United States census, 2020 U.S. census, Nashville is the List of muni ...

, on June 20, 1884, to Alice Rosamond (Phillips) and Ebenezer Calvert (1850–1924). She was the eldest of their four daughters. Her father's elder sister Rhoda had married the astronomer Edward Emerson Barnard, and out of respect, her parents had called her sister Alice Barnard Calvert. Her father and his younger brother Peter Ross Calvert (1855–1931) ran Calvert Photography Studio above the United Cigar Store at the southeast corner of 4th and Union Streets in Nashville. The studio was founded by J. H. Van Stavoren; Rodney Poole bought it at a chancery court sale in 1871, and the Calvert brothers bought it from Poole in 1896.

Career

In 1905, she started work at Yerkes Observatory, Wisconsin, as assistant and computer for her uncle who was also professor of astronomy at the

University of Chicago The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the b ...

. She stayed at her uncle's house whilst employed by him. He was known for his discovery of the high proper motion of

Barnard's Star Barnard's Star is a red dwarf about six light-years from Earth in the constellation of Ophiuchus. It is the fourth-nearest-known individual star to the Sun after the three components of the Alpha Centauri system, and the closest star in the ...

. In 1923, when Barnard died, she became curator of the Yerkes photographic plate collection and a high-level assistant, until her retirement in 1946. Barnard's work ''A Photographic Atlas of Selected Regions of the Milky Way'' was completed after his death in 1923 by

Edwin B. Frost Edwin Brant Frost II (July 14, 1866 – May 14, 1935) was an American astronomer. Biography He was born in Brattleboro, Vermont. His father, Carlton Pennington Frost, was dean of Dartmouth Medical School. Frost graduated from Dartmouth in ...

, director of the Yerkes Observatory, and Calvert. The work was nominally his although Calvert had done the preliminary work under his supervision, but it was she who did the computations necessary to complete the tables, numbered and sketched in darker objects added annotation to the reference stars. Calvert and Frost decided that it should be published in two volumes. The atlas contained 349 dark objects although later editions covered 352 as three had been omitted by mistake. There were several more dark objects that were on the plates but that were not catalogued possibly due to Barnard's death, as both Calvert and Barnard had been aware of them. Only 700 copies were printed in 1927, making the original edition a collector's item. ''The Astronomy Compendium'' calls it a "seminal work". In 1934 she and

Frank Elmore Ross Frank Elmore Ross (April 2, 1874 – September 21, 1960) was an American astronomer and physicist. He was born in San Francisco, California and died in Altadena, California. In 1901 he received his doctorate from the University of California ...

published a photographic study, ''Atlas of the Northern Milky Way'', based on Ross's photographs.

Later life

After she retired from Yerkes in 1946, she received no pension. She returned to Nashville, where she worked in her sister's photographic studio part-time. She died in Nashville in 1974.

Publications

* ''Atlas of the Northern Milky Way'' (with

), University of Chicago Press (1934)

References

External links