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Shapley,
Harlow American astronomer Born: Nashville, Missouri, November 2, 1885 Died: , | |||||||||
Brahe Galileo Herschel Hevelius Hubble Kepler Leavitt Messier Shapley |
Harlow Shapley graduated from the University of Missouri in 1910 and went on to obtain a doctorate from Princeton University. He began work at the Mount Wilson Observatory, California in 1914. Shapley began to study the globular clusters, which were immense closely-packed groups of bodies, some containing more than a million stars and other objects. There were approximately a hundred such objects known, and more than a third of them were to be found in one constellation - Sagittarius. Using the Cepheid measurement worked out by Leavitt, several years before, Shapley applied the period-luminosity curve to the Cepheid stars in each globular cluster, using their period and apparent brightness to determine the distance to the various clusters. Upon plotting these various distances, he found that the clusters were distributed in a sphere around a point originating approximately in the center of Sagittarius. It was quickly deduced from these findings that this point was the center of our galaxy, the Milky Way, which lies about 30,000 light years from Earth. This was an important discovery and was the first to present a picture of our galaxy which displayed it's true size. It marked the beginning of galactic astronomy, a field that was considerably advanced by Hubble. Shapley was appointed director of the Harvard Observatory in 1921, where he remained for the duration of his career. | |||||||||
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