Horace W. Babcock | |
|---|---|
 Babcock in 1976 | |
| Born | (1912-09-13)September 13, 1912 |
| Died | August 29, 2003(2003-08-29) (aged 90) |
| Known for | Adaptive Optics Babcock Model |
| Awards | Henry Draper Medal(1957) Eddington Medal(1958) Bruce Medal(1969) Gold Medal of the Royal Astronomical Society(1970) George Ellery Hale Prize(1992) |
| Scientific career | |
| Fields | astronomy |
Horace Welcome Babcock (September 13, 1912 – August 29, 2003) was an Americanastronomer. He was the son ofHarold D. Babcock.
Babcock invented and built several astronomical instruments and was the first to proposeadaptive optics in 1953.[1][2] He specialized inspectroscopy and the study ofmagnetic fields of stars. He proposed theBabcock Model, a theory for the magnetism ofsunspots.
DuringWorld War II, he was engaged inradiation work atMIT andCaltech. After the war, he began a productive collaboration with his father. His undergraduate studies were atCaltech, and his doctorate was from theUniversity of California, Berkeley.[3]
Babcock's 1938 doctoral thesis contained one of the earliest discoveries ofdark matter. He reported measurements of the rotation curve for the Andromeda galaxy (M31) and wrote, "The velocities therefore indicate a greater mass than that derived from the luminosity. This discrepancy can hardly be explained unless we postulate either a change in the nature of the stellar population in the outer parts of the nebula or a departure from the laws of circular motion," and "the mass-to-light ratio increases markedly at large radii. It is evident that the outer parts of the nebula contain either a great amount of non-luminous matter or that the motions depart significantly from circularity."[4] Babcock considered the possibility that there was more dust in the outer parts of the galaxy than previously thought, thereby increasing the mass-to-light ratio, but did not conclude this was the explanation. Nonetheless, it was not until the work of Morton (Mort) Roberts[5] in the late 1960s, Rubin & Ford,[6] and Freeman in regard toNGC 300,[7] that attention to spiral galaxy rotation curves was again in the spotlight as an indication of a mass or gravity problem in spiral galaxies.[8]
Babcock was director of thePalomar Observatory forCaltech from 1964 to 1978.[9]
Awards
Named after him
Honors
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| National | |
| Other | |
