The Bruce Medalists


  portrait Photo c. 1953, courtesy Dr. Babcock
Horace Welcome Babcock
13 September 1912 1969 Bruce Medalist 29 August 2003

Horace Babcock was born in California and earned his B.S. at the California Institute of Technology and his Ph.D. at the University of California at Berkeley. For his doctorate he determined the rotation curve of the Andromeda Galaxy M31, showing that the mass to light ratio increased going outward from the nucleus. Much later his measurements would be considered an early indication of the existence of dark matter. After a stint at the Yerkes and MacDonald Observatories, where he designed a fast nebular spectrograph, and war work at MIT and Caltech, Babcock joined the staff of the Mt. Wilson (soon to be Mt. Wilson and Palomar) Observatory in 1946. There he invented and built many astronomical instruments, including the solar magnetograph, and microphotometers, automatic guiders, and exposure meters for the 100 and 200-inch telescopes. He often worked closely with his father, Harold Babcock, whom he succeeded in 1948 as head of the diffraction grating laboratory, which built the world’s best gratings at the time. The two Babcocks were first to measure the distribution of magnetic fields over the solar surface. By combining his polarizing analyzer with the spectrograph Horace Babcock discovered magnetic fields in other stars. He developed important models of sunspots and their magnetism, and in 1953 he was the first to propose adaptive optics. He directed the Mt. Wilson and Palomar (later Hale) Observatories from 1964 to 1978. During this time he led in founding the Las Campanas Observatory in Chile. He continued working on innovative projects in instrumentation after retirement.

Presentation of Bruce medal
Abell, George W., PASP 81, 179-83 (1969).

Other awards
American Astronomical Society Solar Physics Division, George Ellery Hale Prize, 1992.
National Academy of Sciences, Henry Draper Medal, 1957.
Royal Astronomical Society, Eddington medal, 1958; Gold medal 1970, presented by B. Lovell, QJRAS 11, 85-87 (1970). See also Physics Today 23, 5, 91 (1970).

Biographical materials
A Dictionary of Scientists (Oxford University Press, Oxford, UK, 1999).
Observatories of the Carnegie Institution of Washington, Horace Babcock Memorial Symposium
Preston, George W., Biographical Memoirs of the National Academy of Sciences (2008).

Baliunas, Sallie, Mercury 32, 6, 45 (Nov/Dec 2003).
McFarling, Usha Lee, Los Angeles Times, 3 September 2003.
O’Connor, Anahad, New York Times, 5 September 2003
Preston, George W., PASP 116, 290-94 (2004).
Sandage, Allan, Proceedings of the American Philosophical Society 150, 151-60 (2006).
Vaughn, Arthur H., Bull. Am. Astron. Soc. 35, 1454-55 (2003)

AIP Center for History of Physics
Caltech Archives (4 photos)
Huntington Library (many)

Named after him
Minor Planet #3167 Babcock (with H.D. Babcock)

More references

The Bruce Medalists

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