John Adelbert Parkhurst (September 24, 1861 – March 1, 1925) was an American

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 ...

. He was born in

Dixon, Illinois Dixon is a city in Lee County, Illinois, United States, and its county seat. The population was 15,274 as of the 2020 census. The city is named after founder John Dixon, who operated a rope ferry service across the Rock River (Mississippi River ...

, and attended the public schools in Marengo, IL and Wheaton College. He then attended Rose Polytechnic Institute in

Terre Haute, Indiana Terre Haute ( ) is a city in Vigo County, Indiana, United States, and its county seat. As of the 2020 United States census, 2020 census, the city had a population of 58,389 and Terre Haute metropolitan area, its metropolitan area had a populati ...

, earning a

B.Sc. A Bachelor of Science (BS, BSc, B.S., B.Sc., SB, or ScB; from the Latin ') is a bachelor's degree that is awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Scienc ...

in 1886. For the following two years he taught mathematics at the same school. He was the son of Sanford Britton Parkhurst and Jane Clarissa Hubbard. Source: George Parkhurst Increasings by Peter G. Parkhurst, p. 402. In 1888 he married Anna Greenleaf. He returned to

Marengo, Illinois Marengo is a city in McHenry County, Illinois, McHenry County, Illinois, United States on the Kishwaukee River. It lies approximately 60 miles west northwest of Chicago, Illinois, Chicago and approximately 30 miles east of Rockford, Illinois, Ro ...

where he kept a small, private observatory that he used primarily for variable star observation.

Yerkes Observatory Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 until 2018. O ...

was built nearby in 1897, and in 1898 he joined the staff as a volunteer research assistant. By 1900 he was appointed as an assistant. He remained on the staff for 25 years, later becoming an associate professor at the

University of Chicago The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...

, specializing in practical astronomy. His most important work was in the specialty of

photometry Photometry can refer to: * Photometry (optics), the science of measurement of visible light in terms of its perceived brightness to human vision * Photometry (astronomy), the measurement of the flux or intensity of an astronomical object's electr ...

. He also participated in three eclipse expeditions, but only enjoyed clear seeing conditions on the last (1925). During his career he published about 100 papers on astronomy, both before and during his time at Yerkes. In 1905 he was elected a fellow of the

Royal Astronomical Society The Royal Astronomical Society (RAS) is a learned society and charitable organisation, charity that encourages and promotes the study of astronomy, planetary science, solar-system science, geophysics and closely related branches of science. Its ...

. On February 27, 1925, he suffered a

cerebral hemorrhage Intracerebral hemorrhage (ICH), also known as hemorrhagic stroke, is a sudden bleeding into the tissues of the brain (i.e. the parenchyma), into its ventricles, or into both. An ICH is a type of bleeding within the skull and one kind of stro ...

and died a few days later at his home in Williams Bay. He was survived by his wife, Anna. The crater Parkhurst on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

is named after him. Parkhurst Place in Williams Bay is also named for him. This street leads into the east side of

and wraps around into the South Lawn. Parkhurst Place is where many noteworthy astronomers and astronomy educators of the 20th Century lived including

Subramanyan Chandrasekhar Subrahmanyan Chandrasekhar (; 19 October 1910 – 21 August 1995) was an Indian-American theoretical physicist who made significant contributions to the scientific knowledge about the structure of stars, stellar evolution and black holes. He wa ...

, William Wilson Morgan,

Otto Struve Otto Lyudvigovich Struve (; 12 August 1897 – 6 April 1963) was a Russian-American astronomer of Baltic German origin. Otto was the descendant of famous astronomers of the Struve family; he was the son of Ludwig Struve, grandson of Otto Wilhel ...

, Franklin E. Roach, and

George Ellery Hale George Ellery Hale (June 29, 1868 – February 21, 1938) was an American astrophysicist, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-leading ...

References

* ''

Dictionary of Scientific Biography The ''Dictionary of Scientific Biography'' is a scholarly reference work that was published from 1970 through 1980 by publisher Charles Scribner's Sons, with main editor the science historian Charles Coulston Gillispie, Charles Gillispie, from Pri ...

''. Vol. 10. New York 1975, p. 320-321. * "Obituary Notices: Fellows:- Parkhurst, John A",

Monthly Notices of the Royal Astronomical Society ''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal in astronomy, astrophysics and related fields. It publishes original research in two formats: papers (of any length) and letters (limited to ...

, Vol. 86, 1926, p. 185-186

{{DEFAULTSORT:Parkhurst, John Adelbert 1861 births 1925 deaths American astronomers