Americanastronomer and mathematician. In 1892 he studied the spectral changes of Nova Aurigae. In 1896 he began a long series of measurements of stellar radial velocities, publishing a catalogue of 3000 of them in 1928. This work improved knowledge of the Sun's motion in the Galaxy and of the Galaxy's rotation. Campbell led several expeditions to solar eclipses. At the eclipse of 1922 he detected the deflection of starlight by the Sun, as predicted by Einstein's theory of general relativity, confirming and improving the previous results of F. W. Dyson and A. S. Eddington.
Subjects: Astronomy and Astrophysics.