Plaskett enrolled as an undergraduate in mathematics and physics at the University of Toronto in 1895 and earned his diploma four years later in 1899 at the age of 33.
Career
Gallery of John Plaskett
John Stanley Plaskett at work at the University of Toronto. Source: Royal Astronomical Society of Canada.
Gallery of John Plaskett
Dominion Astrophysical Observatory, 5071 W Saanich Rd, Victoria, BC V9E 2E7, Canada
John Stanley Plaskett with colleagues at the Dominion Astrophysical Observatory.
Gallery of John Plaskett
John Stanley Plaskett
Gallery of John Plaskett
John Stanley Plaskett at his office.
Achievements
Membership
Royal Society of London
Royal Society, 6–9 Carlton House Terrace, London, England, United Kingdom
Plaskett was elected a fellow of the Royal Society.
Awards
Gold Medal of the Royal Astronomical Society
1930
John Stanley Plaskett was awarded the Gold Medal of the Royal Astronomical Society.
Rumford Prize
1930
John Stanley Plaskett was awarded the Rumford Prize issued by the American Academy of Arts and Sciences, is one of the oldest scientific prizes in the United States.
Bruce Medal
1932
John Stanley Plaskett was awarded the Bruce Medal issued by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy.
Henry Draper Medal
1934
Plaskett was awarded the Henry Draper Medal by the United States National Academy of Sciences "for investigations in astronomical physics".
Order of the British Empire
Plaskett was given the Most Excellent Order of the British Empire, which is a British order of chivalry, rewarding contributions to the arts and sciences, work with charitable and welfare organizations, and public service outside the civil service.
John Stanley Plaskett was awarded the Rumford Prize issued by the American Academy of Arts and Sciences, is one of the oldest scientific prizes in the United States.
John Stanley Plaskett was awarded the Bruce Medal issued by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy.
Plaskett was given the Most Excellent Order of the British Empire, which is a British order of chivalry, rewarding contributions to the arts and sciences, work with charitable and welfare organizations, and public service outside the civil service.
Plaskett enrolled as an undergraduate in mathematics and physics at the University of Toronto in 1895 and earned his diploma four years later in 1899 at the age of 33.
John Stanley Plaskett was a Canadian astronomer. Plaskett’s chief contributions to astronomy were in instrumental design and the supervision of a lengthy program of observation, especially of spectroscopic binary stars. In 1922, he discovered a binary star and the larger of the two still holds the record as the most massive known binary star, which is known today as “Plaskett’s Star”.
Background
John Stanley Plaskett was born on January 17, 1865, on a farm in Hickson, Ontario. Plaskett was the son of Joseph and Annie Plaskett. His father died when he was about 16, and as the eldest child of a large family, he spent the next five years working on the family farm.
Education
Plaskett first was educated at the local village school and the Woodstock High School. Determined to obtain a university education, he enrolled in the bachelor’s program at the University of Toronto in 1895 and earned his diploma four years later in 1899 at the age of 33. Plaskett received four honorary doctoral degrees from Canadian and American universities during his career.
After Plaskett left school, he began to work on the family farm but soon was employed by a mechanic in Woodstock. He then went to the Edison Electric Company, first in Schenectady, New York, and later in Sherbrooke, Quebec. In 1889 Plaskett was a mechanic in the department of physics at the University of Toronto. He took the opportunity first to matriculate and then to take up undergraduate studies, which he followed concurrently with his other work. He eventually graduated in physics and mathematics in 1899. He remained a mechanic until 1903, but in his final years at Toronto, he was engaged in research in color photography.
From 1903 Plaskett was on the staff of the new Dominion Observatory in Ottawa. He worked with the spectrograph and measured radial velocities with the fifteen-inch reflector; and after making a careful study of the mechanical problems involved and discussing the matter with the staffs of many American observatories, he designed a new spectrograph for the reflector. It is claimed that his design so increased the speed of this instrument that for radial velocity work it became the equal of the Yerkes refractor.
After persistently recommending that the Canadian Parliament build a seventy-two-inch reflector, Plaskett prevailed and the contracts were signed in 1913. Much of the design was Plaskett’s own. In 1917 he was appointed a director of the Dominion Astrophysical Observatory in Victoria, British Columbia, which opened in 1918. Again he and his staff concentrated on the observation of radial velocities. New binaries were discovered and their orbits measured, these binaries including “Plaskett's twins.” This star system, which Plaskett was the first to realize was not a single star (B.D. 4-6° 1309), was long the most massive known (1922).
He gave particular attention to early-type O and B stars, and he studied the motion and distribution of interstellar calcium. But perhaps his most notable achievement was his application of spectroscopic evidence to the problem of galactic rotation and the distance and direction of the center of gravity of the galaxy, those being determined from the motions of stars of spectral types 05 to B7 (1930).
Plaskett retired in 1935. After his retirement, he supervised the grinding and polishing of the eighty-two-inch mirror for the McDonald Observatory at the University of Texas.
Plaskett was elected a fellow of the Royal Society, was a member and a president of the Royal Astronomical Society of Canada.
Royal Society of London
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United Kingdom
Connections
In 1892 John Stanley Plaskett was married to Rebecca Hope Hemley. One of his two sons, Harry Hemley Plaskett, became Savilian professor of astronomy at Oxford. He also pursued a very successful career in astronomy, winning the Gold Medal of the Royal Astronomical Society in 1963, thereby, making the Plasketts one of the very few families to boast more than one Medal winner.