Olin Chaddock Wilson (January 13, 1909 – July 13, 1994) was an American

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

best known for his work as a stellar

spectroscopist Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wav ...

. Born in San Francisco, California as the son of a lawyer, Wilson showed an interest in physics at an early age. He studied astronomy and physics at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

and wrote his first scientific paper in 1932 on the subject of the

speed of light The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit ...

. He received his PhD from the

California Institute of Technology The California Institute of Technology (branded as Caltech or CIT)The university itself only spells its short form as "Caltech"; the institution considers other spellings such a"Cal Tech" and "CalTech" incorrect. The institute is also occasional ...

in 1934. Wilson was a staff member of

Mount Wilson Observatory The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observat ...

(not named after Olin Wilson) for most of his research career where he studied stellar chromospheres. He was the first scientist to discover activity cycles, similar to the solar 11-year sunspot cycle, in other stars. In collaboration with Vainu Bappu, an Indian astronomer, he also showed that there was a correlation between the width of the Ca II lines in stellar spectra and the star's luminosity, the

Wilson–Bappu effect The Ca II K line in cool stars is among the strongest emission lines which originates in the star's chromosphere. In 1957, Olin C. Wilson and M. K. Vainu Bappu reported on the remarkable correlation between the measured width of the aforemen ...

. He gave the Henry Norris Russell Lectureship in 1977 and won the

Bruce Medal The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was fi ...

in 1984.

References

External links

National Academy of Sciences biography
1909 births 1994 deaths American astronomers {{US-astronomer-stub