Henry Crozier Keating Plummer FRS FRAS (24 October 1875 – 30 September 1946) was an

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

Early years and education

Born in

Oxford Oxford () is a city in England. It is the county town and only city of Oxfordshire. In 2020, its population was estimated at 151,584. It is north-west of London, south-east of Birmingham and north-east of Bristol. The city is home to the ...

, Plummer was the son of William Edward Plummer (1849–1928) and nephew of the distinguished astronomer John Isaac Plummer (1845-1925). He gained his education at St. Edward's School and then Hertford College at Oxford University. After studies in

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

, he became a lecturer at

Owen's College The Victoria University of Manchester, usually referred to as simply the University of Manchester, was a university in Manchester, England. It was founded in 1851 as Owens College. In 1880, the college joined the federal Victoria University. Afte ...

Manchester Manchester () is a city in Greater Manchester, England. It had a population of 552,000 in 2021. It is bordered by the Cheshire Plain to the south, the Pennines to the north and east, and the neighbouring city of Salford to the west. The t ...

, instructing in mathematics.

Career

In 1900, he became an assistant at the

Radcliffe Observatory Radcliffe Observatory was the astronomical observatory of the University of Oxford from 1773 until 1934, when the Radcliffe Trustees sold it and built a new observatory in Pretoria, South Africa. It is a Grade I listed building. Today, the ...

, where his father had served previously. He remained there for most of the next twelve years, spending one year at Lick Observatory as a Research Fellow. In 1912, he was appointed to the position of

Andrews Professor of Astronomy The Andrews Professor of Astronomy is a chair in astronomy in Trinity College Dublin was established in 1783 in conjunction with the establishment of Dunsink Observatory. Dunsink was founded in 1785 following a bequest by Provost Francis Andre ...

at Trinity College, Dublin, which carried with it the title of

Royal Astronomer of Ireland The Dunsink Observatory is an astronomical observatory established in 1785 in the townland of Dunsink in the outskirts of the city of Dublin, Ireland. Alexander Thom''Irish Almanac and Official Directory''7th ed., 1850 p. 258. Retrieved: 2011-02 ...

. He was the last holder of both positions. He was the director of the

Dunsink Observatory The Dunsink Observatory is an astronomical observatory established in 1785 in the townland of Dunsink in the outskirts of the city of Dublin, Ireland.Alexander Thom''Irish Almanac and Official Directory''7th ed., 1850 p. 258. Retrieved: 2011-02-2 ...

from 1912 to 1920. He joined the Military College of Science at

Woolwich Woolwich () is a district in southeast London, England, within the Royal Borough of Greenwich. The district's location on the River Thames led to its status as an important naval, military and industrial area; a role that was maintained thr ...

in 1921, as professor of mathematics. He would remain at Woolwich until he retired in 1940, becoming President of the

Royal Astronomical Society (Whatever shines should be observed) , predecessor = , successor = , formation = , founder = , extinction = , merger = , merged = , type = NG ...

from 1939 until 1941. During his career he contributed to the

Astrographic Catalogue The Carte du Ciel (literally, 'Map of the Sky') and the Astrographic Catalogue (or Astrographic Chart) were two distinct but connected components of a massive international astronomical project, initiated in the late 19th century, to catalogue an ...

, and contributed scientific papers. His investigations included photometric observations of short-period variables, and the radial pulsations of

cepheid variable A Cepheid variable () is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid vari ...

s. In 1911, he developed a gravitational potential function that can be used to model globular clusters and spherically symmetric galaxies, known as the Plummer potential. In 1918 he published the work
''An Introductory Treatise on Dynamical Astronomy.''
He also made studies of the history of science, and served on the Royal Society committee that was formed to publish the papers of Sir

Isaac Newton Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a " natural philosopher"), widely recognised as one of the grea ...

Awards and honors

* Fellow of the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

, 1920 * Fellow of the Royal Astronomical Society, 1899. * The crater Plummer on the Moon is named after him.

References

;General * W. M. Smart, (Plummer, Henry Crozier Keating) Obituary, ''Monthly Notices of the Royal Astronomical Society'', vol. 107, February 1947, pp. 56–59.

Publications

* On the Theory of Aberration and the Principle of Relativity, 1910,

Monthly Notices of the Royal Astronomical Society ''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting orig ...

, Vol. 70, pp. 252–266

External links

John Isaac Plummer
with a brief biography of Henry.
Mr. Henry C. K. Plummer, M.A., Hertford College, Oxford
The St. Edward's School Chronicle, No. 312, Vol. XII. May, 1912. {{DEFAULTSORT:Plummer, Henry Crozier Keating 1875 births 1946 deaths Academics of the University of Oxford Alumni of Hertford College, Oxford Directors of Dunsink Observatory 20th-century British astronomers Fellows of the Royal Society Fellows of Trinity College Dublin 20th-century Irish astronomers People educated at St Edward's School, Oxford Presidents of the Royal Astronomical Society