Shapley, Harlow (1885-1972), was an American astronomer who helped determine the size of the Milky Way Galaxy and our solar system’s location within it. Shapley studied variable stars (stars that change in brightness) and the dense groups of stars where they are often found. He observed a high concentration of these star groups, called globular clusters, near the center of the Milky Way. Shapley measured the brightness of variable stars in these clusters to calculate their distance from Earth. He found that our solar system is closer to the edge of the galaxy than to its center. He also showed that the Milky Way is much larger than astronomers had believed it was. Shapley later studied two nearby galaxies known as the Magellanic Clouds.
Harlow Shapley was born on Nov. 2, 1885, in Nashville, Missouri. He earned a Ph.D. degree from Princeton University in 1913. Shapley served as director of the Harvard Observatory from 1921 to 1952. He died in Boulder, Colorado, on Oct. 20, 1972.
See also Milky Way ; Star cluster .
