Joy, Alfred H. (Alfred Harrison), 1882-1973

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Alfred Harrison Joy (1882-1973), an American astronomer who spent most of his professional career at the Mount Wilson Observatory studying stellar radial velocities, variable stars, T Tauri stars, and galactic structure. He was president of the American Astronomical Society and of the Astronomical Society of the Pacific (he was also a recipient of the Society's Bruce Gold Medal).

From the description of Papers of Alfred Harrison Joy, 1910-1972. (Huntington Library, Art Collections & Botanical Gardens). WorldCat record id: 228721191

Biographical Note

Alfred Harrison Joy was a distinguished stellar astronomer who spent most of his professional career at the Mount Wilson Observatory. His work on stellar radial velocities, variable stars, and galactic structure in the early twentieth century laid the groundwork for the rapidly expanding field of astrophysics. His pioneering work, his long tenure at Mount Wilson, his central roles in the Astronomical Society of the Pacific and American Astronomical Society, and his position as Secretary of the Observatory make him a significant figure in the history of astronomy.

Alfred H. Joy was born in Greenville, Illinois, on September 23, 1882 to Frank and Louise (Maynard) Joy. Little is known of his early years, but it appears that Joy's mother passed on to her son a great love of science. When it was time for him to go to college, he went to a small local school, Greenville College, operated by the Free Methodist Church. He took his degree in 1903 in Latin and science, graduating in a class of seven. Joy then spent the next year at Oberlin College in Ohio, obtaining an M.A. in physics. His teacher at Oberlin was Charles E. St. John, who would later become his colleague at Mount Wilson.

Upon receiving his M.A. in 1904, Joy immediately obtained a teaching position at the American University of Beirut. He was the instructor of physics at Beirut and this included teaching astronomy. Over the years, his abilities and interest in astronomy grew, helped by his participation in the 1905 Lick Observatory eclipse expedition in Egypt, the transit of Mercury, and observations of the 1910 apparition of Halley's comet. In 1909, Joy spent the summer in Oxford and Cambridge working on the Carte du Ciel project. In the summer of 1910, Joy worked as an assistant at the Yerkes Observatory. And in the 1910-11 academic year he obtained a Thaw fellowship to Princeton where he received valuable astronomy instruction from Henry Norris Russell. Joy's notebooks from Russell's classes are a valuable part of this collection (the "classes" were one-on-one instruction sessions with Russell at his Princeton home). This period, from 1909 to 1911, was crucial in shaping Joy's future astronomical interests.

Joy returned to Beirut in 1911 where he had recently been appointed director of the Observatory. In 1914, he traveled to Potsdam, Germany, to continue his research interests. At Potsdam he came into contact with Karl Schwarzschild and Ejnar Hertzsprung, two important figures in the growing field of astrophysics. Joy then went to the Yerkes Observatory for a second time to help in their stellar parallax program. By 1915, however, the First World War was well underway and Joy found it impossible to get back to Beirut. Fortunately for him, he had come to the attention of George Ellery Hale at Mount Wilson, and Hale soon offered Joy a permanent position at Mount Wilson, a position he held until his retirement thirty-three years later in 1948.

While Joy's first year at Mount Wilson saw work on solar matters, he soon became involved in the stellar spectroscopy work headed by Walter S. Adams. Earlier, Adams and Kohlsch|tter had learned how to accurately determine a star's spectral class and absolute luminosity. Using this information it became possible for them to calculate the distance to the star, a quantity referred to as its "spectroscopic parallax." Joy worked at deciphering numerous stellar spectra until, in 1935, Joy and Adams had published a catalogue of spectroscopic parallaxes of 4,179 stars.

Joy soon became involved in the study of variable stars. Splitting the stars among three researchers at Mount Wilson, Joy worked on red semi-regular variable stars. One exception was the remarkable long-period M-type variable, Mira (omicron Ceti). Joy had a fondness for this famous star, perhaps due to his spectroscopic discovery of its faint companion star in 1920. Noting the odd spectrum, Joy had written to R. G. Aitken at Lick to see if he could visually observe the companion in their large refracting telescope. Aitken soon saw the faint star, thus confirming Joy's discovery. Joy also amassed a great deal of information on the W Virginis (Population II) Cepheids and RR Lyrae stars, material that has led to a greater understanding of our Galaxy.

Joy's work on variable stars led to many new results which increased astronomers' understanding of these peculiar objects. He showed in 1933 that the emission lines in RW Tauri's spectrum were due to a small Saturn-like ring around the brighter primary star. Joy identified many spectroscopic binaries and initiated spectroscopic studies of dwarf novae.

Another of Joy's important researches was his study of galactic rotation. From his earlier studies of the radial velocity of Cepheid variables, he collected a large sample of data and demonstrated that the Population I Cepheids constituted a low-velocity family of stars and was able to calculate the coordinates of the Galaxy's center.

Perhaps Joy's most far-reaching work was that on the T Tauri stars. This came about because of his study of M-type dwarfs. Joy became acquainted with these latter stars during his work with Adams. As Joy became interested in the M dwarfs' habit of "flaring," he came across the unusual star UZ Tauri. This type of star, described by Joy as a T Tauri variable in 1945, later proved to be the transition between interstellar clouds and main-sequence stars.

In 1919, Joy married Margherita O. Burns, a computer at the Observatory. The next year, he was appointed Secretary of the Observatory. In this new position, Joy was constantly in contact with the community and press regarding astronomical matters in general and happenings at the Mount Wilson Observatory in particular. Joy remained as Secretary, in addition to his other duties, until his retirement in 1948.

Joy's most infamous feat was his unfortunate accident in 1946 at the age of sixty-four when he fell twenty feet from the Cassegrain platform of the 100-inch telescope to the cement floor. Breaking an arm, a leg, and his hip, Joy was hospitalized but with characteristic vigor, was back observing eight months later.

A great deal of correspondence in the collection is with the Astronomical Society of the Pacific. Joy served in many capacities with this organization, being on its Board of Directors, President in 1931 and 1939, and from 1945 to 1968, editor of the Leaflets, a monthly issuance of small eight page reports for laymen and astronomers on new results in astronomy. In 1950, the Society presented Joy with its highest award, the Bruce Gold Medal. Joy was active in other organizations as well, particularly the American Astronomical Society, being its President from 1949 to 1952. In 1949, Joy was elected to the National Academy of Sciences and in 1964 was named an Associate of the Royal Astronomical Society. In closing, perhaps the best description of Joy comes from his close friend George H. Herbig: "His scientific work was typical of the man himself: it was done quietly, patiently, with gentle humor, with great honesty and generosity. It was accomplished without fanfare, published without arrogance or pretence, and with recognition of the debt he owed to others. Joy was usually content simply to report what he had seen or done, in the conviction that speculation or over-interpretation is often evanescent, but that solid observations would inevitably survive."

From the guide to the Alfred Harrison Joy Papers, 1910-1972, (The Huntington Library)

Archival Resources
Role Title Holding Repository
creatorOf Alfred Harrison Joy Papers, 1910-1972 The Huntington Library
creatorOf Hale, George Ellery, 1868-1938. Mount Wilson Director's papers, 1901-1925. Huntington Library, Art Collections & Botanical Gardens
creatorOf Swope, Henrietta Hill, 1902-. Papers of Henrietta Hill Swope, 1923-1979. Huntington Library, Art Collections & Botanical Gardens
creatorOf Joy, Alfred H. (Alfred Harrison), 1882-1973. Papers of Alfred Harrison Joy, 1910-1972. Huntington Library, Art Collections & Botanical Gardens
creatorOf Pettit, Edison, 1889-1962. Papers of Edison Pettit, 1920-1969. Huntington Library, Art Collections & Botanical Gardens
Role Title Holding Repository
Relation Name
associatedWith Abt, Helmut A. person
associatedWith Adams, Ansel, 1902-1984. person
associatedWith Aitken, Robert Grant, 1864-1951. person
associatedWith American Astronomical Society. corporateBody
associatedWith Astronomical Society of the Pacific. corporateBody
associatedWith Carnegie Institution of Washington. corporateBody
associatedWith Hale, George Ellery, 1868-1938. person
associatedWith Herbig, G. H. (George H.) person
associatedWith Hogg, Helen Sawyer, 1905-1993. person
associatedWith Kuiper, Gerard P. (Gerard Peter), 1905-1973. person
associatedWith Luyten, Willem Jacob, 1899-1994. person
associatedWith Lynds, Beverly T. person
associatedWith Merrill, Paul W. (Paul Willard), 1887-1961. person
associatedWith Mount Wilson Observatory corporateBody
associatedWith Page, Thornton. person
associatedWith Pettit, Edison, 1889-1962. person
associatedWith Plavec, Miroslav. person
associatedWith Seares, Frederick Hanley, 1873- person
associatedWith Swope, Henrietta Hill, 1902-. person
associatedWith Vyssotsky, A. N. (Alexander N.), b. 1888. person
Place Name Admin Code Country
California, Southern
T Tauri stars
Variable stars


Birth 1882-09-23

Death 1973-04-18



Ark ID: w64x6mbk

SNAC ID: 3504936