Keenan, Philip Childs

Born Bellevue, Pennsylvania, USA, 31 March 1908

Died Columbus, Ohio, USA, 20 April 2000

American spectroscopist Philip Keenan was the first "K" of MKK spectral types (where M = William Morgan and the second K = Edith Kellman), one of the primary ways of classifying stars from 1943 down to the present. The elder son of Charles Gaskell Keenan and Eveylyn Larrabee (née Childs) Keenan, he was discovered by the Stanford University psychologist Lewis M. Terman, after the family moved to Ojai, in central California. Terman included him in a sample of about 1,000 children with high intelligence quotients (above 135), and other indications of exceptional brilliance, whom he followed for many decades, showing that Keenan was quite typical of the group in outstanding later achievements.

Keenan received his BS from the University of Arizona in 1929, publishing his first paper (on the color of the Moon during total eclipse, important for understanding transmission of