Alfred Harrison Joy

1950

Date of Birth

September 23, 1882

Date of Death

April 18, 1973

After earning his bachelor’s degree at Greenville College in Illinois and his M.A. at Oberlin College, Alfred Joy taught ten years at the American University of Beirut, where he photographed Halley’s Comet in 1910. He spent several summers and one year at Yerkes Observatory and also studied for short periods at Princeton (under Henry Norris Russell) and several European observatories. When World War I prevented his return to Beirut in 1915 he joined the staff of Mt. Wilson Observatory. He remained active there nearly sixty years, although officially retired after 1948. After early solar work with G.E. Hale’s team, Joy applied Walter S. Adams’s method of spectroscopic parallax to determine the distances of thousands of stars. When he retired nearly half of all published radial velocities of stars had been found at Mt. Wilson, largely through his efforts. He measured radial velocities of Cepheid variable stars and confirmed the distance and direction of the Galactic center and the sun’s rate of revolution about it. He specialized in the spectroscopy of variable stars, and also studied spectra of comets and novae. He invented the classification of T Tauri stars and made extensive studies of them. He edited the popular Leaflets of the Astronomical Society of the Pacific from 1945 to 1968.

Obituaries

Abt, Helmut A., Mercury 2, 3, 15 and 2, 5, 9-10 (1973).
Herbig, George H., QJRAS 15, 526-31 (1974).

Portraits

AIP Center for History of Physics
90th birthday photo, 1972, courtesy Observatories of the Carnegie Institution of Washington

Named after him

Lunar crater Joy
Minor Planet #11769 Alfredjoy

Bibliography

Papers, etc.

Joy’s papers are at the Huntington Library. Excellent introduction, presumably by archivist Helen S. Czaplicki.

Other References: Historical

Hearnshaw, J. B., The Analysis of Starlight (Cambridge University Press, Cambridge, UK, 1986).

Sandage, Allan, Centennial History of the Carnegie Institution of Washington. Vol. 1, The Mount Wilson Observatory: Breaking the Code of Cosmic Evolution (Cambridge Univ. Press, Cambridge, UK, 2004).

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Other References: Scientific

Joy, Alfred H., “Observations of the Transit of Mercury,” Popular Astronomy 16, 128 (1908).

Joy, Alfred H., “Photometric Measures of BD + 13°4692,” Astr. Nach. 200, 11-12 (1908).

Joy, Alfred H., “An Investigation of the Cluster M 37 (NGC 2099) for Proper-Motion,” Astronomical Journal 29, 101-08 (1915).

Lee, Oliver J., Alfred H. Joy, & Georges van Biesbroeck, “Stellar Parallaxes Derived from Photographs Made with the 40-inch Refractor of the Yerkes Observatory,” Astronomical Journal 30, 1-2 (1916).

Adams, Walter S. & A.H. Joy, “The Luminosities and Parallaxes of Five Hundred Stars. First List,” Ap.J. 46, 313-39 (1917).

Hale, George E., Ferdinand Ellerman, S.B. Nicholson, & A.H. Joy, “The Magnetic Polarity of Sun-Spots,” Ap.J. 49, 153 (1919).

Adams, W.S. & A.H. Joy, “The Motions in Space of Some Stars of High Radial Velocity,” Proc. Natl. Acad. Sci. 5, 23941 (1919).

Adams, W. S., A.H. Joy, G. Strömberg, & C.G. Burwell, “The Parallaxes of 1646 Stars Derived by the Spectroscopic Method,” Ap.J. 53, 13-94 (1921).

Adams, W.S., G. Strömberg, & A.H. Joy, “The Relationship of Absolute Magnitude to Space-Velocity,” Ap.J. 54, 9-27 (1921).

Adams, Walter S. & Alfred H. Joy, “A Spectroscopic Method of Determining the Absolute Magnitudes of A-Type Stars and the Parallaxes of 544 Stars,” Ap.J. 56, 242-64 (1922).

Adams, Walter S. & Alfred H. Joy, “The Radial Velocities of 1013 Stars,” Ap.J. 57, 149-76 (1923).

Adams, Walter S. & Alfred H. Joy, “A Spectroscopic Method of Deriving the Parallaxes of the B-type Stars,” Ap.J. 57, 294-307 (1923).

Russell, H.N., W.S. Adams, & A.H. Joy, “A Comparison of Spectroscopic and Dynamical Parallaxes,” PASP 35, 189-93 (1923).

Adams, W. S. & A.H. Joy, “The Identifications of Certain Enhanced Lines in the Spectra of g Cygni and α Cygni,” PASP 38, 322-24 (1926).

Joy, Alfred H., “A Spectrographic Study of Mira Ceti,” Ap.J. 63, 281-341 (1926).

Adams, Walter S., Alfred H. Joy & M.L. Humason, “The Absolute Magnitudes and Parallaxes of 410 Stars of type M,” Ap.J. 64, 225-42 (1926).

Adams, W.S., M.L. Humason, & A.H. Joy, “Observations of Faint Spectra,” PASP 39, 365-69 (1927).

Adams, Walter Sydney & Alfred H. Joy, “High-Dispersion Stellar Spectra and Some Results of a Study of γ Cygni,” Proc. Natl. Acad. Sci. 13, 393-96 (1927).

Adams, W. S., A. H. Joy, R.F. Sanford & G. Strömberg, “The radial velocities of 741 stars,” Ap.J. 70, 207-36 (1929).

Joy, A. H., “The Dispersion in the Radial Velocities and the Galactic Distribution of Variable Stars of Intermediate and Short Period,” PASP 44, 240-42 (1932).

Adams, Walter S., Alfred H. Joy, Milton L. Humason, & Ada Margaret Brayton, “The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars,” Ap.J. 81, 187-238 (1935).

Adams, Walter S. & Alfred H. Joy, “Spectrum of Nova Herculis 1934, April-November 1935” Ap.J. 84, 14-25 (1936).

Joy, Alfred H., “Radial Velocities of Cepheid Variable Stars,” Ap.J. 86, 363-436 (1937).

Joy, Alfred H., “Rotation Effects, Insterstellar Absorption, and Certain Dynamical Constants of the Galaxy Determined from Cepheid Variables,” Ap.J. 89, 356-76 (1939).

Joy, Alfred H., “Spectroscopic Observations of SS Cygni Variables,” PASP 52, 324-25 (1940).

Joy, A.H., “Observations of RW Tauri at Minimum Light,” PASP 54, 35 (1942). [reprinted in the PASP centennial volume PASP 100, 157-59 (1988) with commentary by Alan H. Batten.]

Joy, Alfred H., “A Survey of the Spectra and Radial Velocities of the Less Regular M-Type Variable Stars,” Ap.J. 96, 344-70 (1942).

Joy, Alfred H., “Spectral Criteria in the Classification of Variable Stars,” PASP 54, 15-18 (1942).

Joy, Alfred H. & Paul W. Merrill, “Spectroscopic Observations of T Arietis,” Ap.J. 98, 331-33 (1943).

Joy, Alfred H., “T Tauri Variable Stars,” Ap.J. 102, 168-95 (1945).

Joy, A.H. & P. Swings, “Identification of the Post-Maximum Lines in the Spectrum of Nova (RS) Ophiuchi.,” Ap.J. 102, 353-56 (1945).

Joy, Alfred H., “Radial Velocities and Spectral Types of 181 Dwarf Stars,” Ap.J. 105, 96-104 (1947).

Joy, Alfred H. & S.A. Mitchell, “Spectroscopic Observations of 90 Stars,” Ap.J. 108, 234-36 (1948).

Joy, Alfred H., “Spectra of the Brighter Variables in Globular Clusters,” Ap.J. 110,105-16 (1949).

Joy, Alfred H. & Ralph E. Wilson, “Stars whose Spectra have Bright H and K Lines of Calcium,” Ap.J. 109, 231-43 (1949).

Joy, Alfred H., “Bright-Line Stars among the Taurus Dark Clouds,” Ap.J. 110, 424-37 (1949).

Wilson, Ralph E. & Alfred H. Joy, “Radial Velocities of 2111 Stars,” Ap.J. 111, 221-61 (1950).

Joy, Alfred H., “The Semiregular Variable Stars of the RV Tauri and Related Classes,” Ap.J. 115, 25-41 (1952).

Joy, Alfred H., “Spectroscopic Observations of Mira Ceti,1934-1952,” Ap.J.Supp. 1, 39-61 (1954).

Joy, Alfred H., “Spectroscopic Observations of AE Aquarii,” Ap.J. 120, 377-83 (1954).

Joy, Alfred H., “Radial-Velocity Measures of SS Cygni at Minimum Light,” Ap.J. 124, 317-30 (1956).

Joy, Alfred H., “The Emission Spectrum of RS Ophiuchi in 1958,” Ap.J. 133, 493-502 (1961).

Joy, Alfred H., “Spectroscopic Absolute Magnitudes: A Review,” JRASC 56, 67-78 (1962).

Joy, Alfred H. & Helmut A. Abt, “Spectral Types of M Dwarf Stars,” Ap.J.Supp. 28, 1-18 (1974).

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Other Works: Popularizations, History, etc.

Joy, Alfred H., “The Mount Wilson Observatory of the Carnegie Institution of Washington,” PASP 39, 9-18 (1927).

Joy, Alfred H., “Eclipsing Stars,” Leaflets of the Astronomical Society of the Pacific 1,77-80 (1928) [Leaflet #19].

Joy, Alfred H., “The Short Period Variable Stars,” Leaflets of the Astronomical Society of the Pacific 1,137-40 (1931) [Leaflet #34].

Joy, Alfred H., “The Temperature of the Stars,” Leaflets of the Astronomical Society of the Pacific 2, 37-40 (1934) [Leaflet #60].

Joy, Alfred H., “Giants and Dwarfs,” Leaflets of the Astronomical Society of the Pacific 2, 97-100 (1935) [Leaflet #75].

Joy, Alfred H., “The Rise of the Giant Telescope,” Leaflets of the Astronomical Society of the Pacific 2, 157-60 (1936) [Leaflet #90].

Joy, Alfred H., “Some Early Variable Star Observers,” Leaflets of the Astronomical Society of the Pacific 2, 193-96 (1937) [Leaflet #99].

Joy, Alfred H., “The Motions and Dimensions of Our Stellar System,” Leaflets of the Astronomical Society of the Pacific 3, 246-53 (1940) [Leaflet #132].

Joy, Alfred H., “A Century’s Progress in Determining Stellar Distances,” Leaflets of the Astronomical Society of the Pacific 4, 176-83 (1943) [Leaflet #173].

Joy, Alfred H., “The Velocity of Light,” Leaflets of the Astronomical Society of the Pacific 4, 362-69 (1945) [Leaflet #195].

Joy, Alfred H., “Refraction in Astronomy,” Leaflets of the Astronomical Society of the Pacific 5, 162-69 (1947) [Leaflet #220].

Joy, Alfred H., “Glowing Stellar Atmospheres,” Leaflets of the Astronomical Society of the Pacific 5, 352-59 (1949) [Leaflet #243].

Joy, Alfred H., “Mira Ceti,” Leaflets of the Astronomical Society of the Pacific 8, 57-64 (1959) [Leaflet #358].

Joy, Alfred H., “The Beginnings of the Astronomical Society of the Pacific,” PASP 76, 1-5 (1964).

Joy, Alfred H., “Seventy-Five Years of the Astronomical Society of the Pacific,” PASP 77, 81-88A (1965).

Joy, Alfred H., “Stellar Flares,” Leaflets of the Astronomical Society of the Pacific 10, 41-48 (1967) [Leaflet #456].

Joy, Alfred H., “Eclipsing Stars,” Leaflets of the Astronomical Society of the Pacific 10, 105-12 (1968) [Leaflet #464].