Abbot, Charles Greeley (1872-1973), a United States astrophysicist and authority on solar radiation. As director of the Smithsonian Astrophysical Observatory, 1907-44, Abbot studied the influence of solar radiation on climate and weather cycles. He perfected instruments for measuring radiation. With Samuel P. Langley, he mapped the infrared spectrum. Abbot was secretary of the Smithsonian Institution from 1928 until 1944, when he became research associate. He was born in Wilton, New Hampshire, and graduated from Massachusetts Institute of Technology.
His writings include The Sun (1911) and The Earth and the Stars (1925, revised edition 1946).