Walter Sydney Adams

Walter Sydney Adams


Date of Birth
December 20, 1876
Date of Death
May 11, 1956

Walter Adams was born in Syria, the son of American missionaries. After receiving his bachelor's degree at Dartmouth College, he accompanied his astronomy professor, Edwin B. Frost, to Yerkes Observatory, where he began graduate study. After two years there and one more year of study at Munich, he was summoned by his Yerkes director, George Ellery Hale, to help establish the Mt. Wilson Solar Observatory. There he served first as Hale's deputy and later as director from 1923 to 1945. His spectroscopic studies of the sun, done with Hale and others, led to the discovery that the sunspots are regions of lower temperatures and stronger magnetic fields than their surroundings. Turning to the stars, he made the discovery, with Arnold Kohlschütter, of a spectroscopic method for determining stellar distances: they showed that the relative intensities of spectral lines could be used to determine absolute magnitudes of both giant and main sequence stars. Adams used photography to measure the differential rotation of the sun. He shared with Theodore Dunham, Jr. in the discoveries of carbon dioxide in the atmosphere of Venus and the molecules CN and CH in interstellar gas clouds. Adams identified Sirius B as the first white dwarf star known, and his measurement of its gravitational redshift was taken as confirming evidence for the general theory of relativity. In retirement he continued his research at the Hale Solar Laboratory in Pasadena, California.

Presentation of Bruce medal

Merrill, Paul W.PASP 40, 2-10 (1928).

Other awards

American Astronomical Society, Henry Norris Russell Lectureship, 1947.
French Academy of Sciences, Janssen Medal, 1935.
National Academy of Sciences, Henry Draper Medal, 1918.
Royal Astronomical Society, Gold medal, 1917, presented by R.A. Sampson, MNRAS 77, 395-410 (1917)
Société Astronomique de France, Janssen Prize, 1926.

Some offices held

American Astronomical Society, President, 1931-34.
Astronomical Society of the Pacific, President, 1923.

Biographical materials

Adams, Sue Kelly, About Walter Sydney Adams’ Role in Making Mt. Wilson and Palomar (Trafford Publishing, Victoria, BC, Canada, 2003).
American Philosophical Society, Adams Papers Background Note
Joy, A.H., Biographical Memoirs of the National Academy of Sciences 31, 1-31 (1958).
Seares, F.H., “Retirement of Dr. Walter S. Adams,” PASP 57, 296-301 (1945).
Stratton, F.J.M., Biographical Memoirs of the Royal Society 2, 1-18 (1956).
Tenn, Joseph S., “Walter S. Adams: The Twenty-Third Bruce Medalist,” Mercury  23, 2, 20 (1994).
Tenn, Joseph S., Biographical Encyclopedia of Astronomers (Springer, NY, 2007), pp. 13-15.
Wright, Helen, Dictionary of Scientific Biography 1, 54-58 (1970-80).


Joy, A.H., PASP 68, 285-95 (1956).
Merrill, Paul W., Year Book of the American Philosophical Society 1956, pp. 103-105.
Merrill, Paul W., “Walter S. Adams, Observer of Sun and Stars,” Science 124, 67 (1956).
Merrill, Paul W., MNRAS 117, 243-44 (1957).
Shapley, Harlow, “A Master of Stellar Spectra,” Sky & Telescope 15, 401 (1956).
Stratton, F.J.M., “Walter S. Adams, 1876-1956,” Observatory 76, 139-140 (1956).


AIP Center for History of Physics
Caltech Archives (many)
Smithsonian Institution (with A. A. Michelson, Walther Mayer, Albert Einstein, Max Ferrrand, & Robert A. Millikan, Caltech, 1931.)

Named after him

Lunar crater Adams (with John Couch Adams and Charles H. Adams)
Mars Crater Adams
Minor Planet #3145 Walter Adams



Papers, etc.

Adams's papers are at the Huntington Library with a Finding Aid by Helen Czaplicki. There is a microform copy at the Caltech Archives. There is much correspondence in the G.E. Hale Papers (now available on microfilm). There is a manuscript autobiography at the AIP Center for History of Physics. There is also some correspondence at the American Philosophical Society.

Other References: Historical

Search ADS for works about Adams

Adams, Walter S., “George Ellery Hale, 1868-1939,” Ap.J. 87, 369-88 (1938).

Adams, W.S., “George Ellery Hale” Biographical Memoirs of the National Academy of Science 21, 181-241 (1939).

Adams, Walter S., “Early Days at Mt. Wilson,” PASP 59, 212-231 and 285-304 (1947).

Adams, W.S., “The Yerkes Observatory, 1898-1904,Science 106, 196-200 (1947).

Adams, W.S., “Some Reminiscences of the Yerkes Observatory,” Science 106, 196-200 (1947).

Adams, Walter S., “The History of the International Astronomical Union,” PASP 61, 5-12 (1949).

Adams, Walter S., “The Founding of the Mount Wilson Observatory,” PASP 66, 267-303 (1954).

Adams, Walter S., “Early Solar Research at Mt. Wilson,” Vistas in Astronomy 1, 619-623 (1955).

Christiansen, Gale E., Edwin Hubble: Mariner of the Nebulae (Farrar, Straus and Giroux, New York, 1995).

Dyson, Frank Watson, “The Stars around the North Pole,” Royal Institution Library of Science: Astronomy, 239-242. (lecture delivered 29 April 1921)

Earman, John & Clark Glymour, “Relativity and Eclipses: The British Eclipse Expeditions of 1919 and Their Predecessors,” Historical Studies in the Physical Sciences 11, 49-85 (1980).

Frost, Edwin B., “The Yerkes Observatory: A Retrospect of Twenty-five Years”, The University Record IX, 1 (1923).

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

Hetherington, Norriss, “Sirius B and the Gravitational Redshift—an Historical Review,” QJRAS 21, 246-252 (1980).  Replies by others, QJRAS 26, 273-278 & 279-288 (1985).

Hetherington, Norriss & Ronald S. Brashear, “Walter S. Adams and the Imposed Settlement Between Edwin Hubble and Adriaan Van Maanen,” Journal for the History of Astronomy 23, 1, 53-56 (1992).

Holberg, J.B., “Sirius B and the Measurement of the Gravitational Redshift,” Journal for the History of Astronomy 41, 41-64 (2010).

Hufbauer, Karl, Exploring the Sun: Solar Science Since Galileo (Johns Hopkins U.P., 1991).

Millikan, Robert A. & Walter S. Adams, “The Reason and the Results of Dr. Einstein's Visit to the California Institute of Technology,” Science 73, 380-81 (1931).

Osterbrock, Donald E., Yerkes Observatory 1892-1950: The Birth, Near Death, and Resurrection of a Scientific Research Institution (Univ. of Chicago Press, Chicago, 1997).

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

Seares, Frederick H., “Retirement of Dr. Walter S. Adams,” PASP 57, 296-301 (1945).

Wright, Helen, Explorer of the Universe: A Biography of George Ellery Hale (Dutton, 1966).

Other References: Scientific

Search ADS for works by Adams.

Hale, George E., Walter S. Adams, & Henry G. Gale, “Preliminary Paper on the Cause of the Characteristic Phenomena of Sun-Spot Spectra,” Ap.J. 24, 185-213 (1906).

Hale, George E. & Walter S. Adams, “Second Paper on the Cause of the Characteristic Phenomena of Sun-Spot Spectra,” Ap.J. 25, 75-94 (1907).

Hale, George E. & Walter S. Adams, “A Photographic Comparison of the Spectra of the Limb and the Center of the Sun,” Ap.J. 25, 300-10 (1907).

Adams, Walter S., “Spectrographic Observations of the Rotation of the Sun,” Ap.J. 26,203-24 (1907).

Adams, Walter S., “Preliminary Catalogue of Lines Affected in Sun-Spots Region λ 4000 to λ 4500,” Ap.J. 27, 45-65 (1908).

Adams, Walter S., “A Spectroscopic Method of Determining Stellar Parallax,” PASP 28, 61-69 (1916) reprinted in PASP 100, 1027-35 (1988), with modern commentary by R.F. Garrison, PASP 100, 1036-40. This is a summary of a series of papers in the Proceedings of the National Academy of Sciences 2, 143, 147, 152, 157 (all 1916), and beginning with Adams, W.S. & A. Kohlschütter, Ap.J. 40, 385-398 (1914).

Other Works: Popularizations, History, etc.

Adams, Walter S., “Astronomical Progress During the Past Year,” PASP 39, 194-98 (1927).

Adams, Walter S., “The Past Twenty Years of Physical Astronomy,” Science 67, 637-44 (1928).

Adams, Walter S., “A Great Telescope and Its Possibilities,” Science 69, 1-8 (1929).

Adams, Walter S., “The Astronomer's Measuring Rods,” PASP 41, 195-211 (1929).

Adams, Walter S., “The Atmospheres of the Planets,” Leaflets of the Astronomical Society of the Pacific 2, 69-72 (1934) [Leaflet #68].

Adams, Walter S., “The 200-inch Telescope,” JRASC 33, 241-46 (1939).

Adams, Walter S., “What Lies Between the Stars?” PASP 53, 73-83 (1941).