Cecilia Payne-Gaposchkin was born in Wendover, England, to Edward Payne, a London barrister, and his wife Emma Pertz. She attended St. Paul's Girls' School in London. In 1919, she won a scholarship to Newnham College, Cambridge University, where she intended to read botany, physics, and chemistry. But after listening to a lecture by astrophysicist Arthur Eddington about solar eclipses, she decided to pursue a career in astronomy. She set up a telescope and was president of the college's Science Society. She completed her studies, but was not awarded a degree because of her gender (Cambridge would not grant degrees to women until 1948). Looking for greater opportunities than she had in the UK, she applied for and won a fellowship to do research at Harvard University. In 1925 she became the first person to earn a Ph.D. in astronomy from Radcliffe College. She met Russian-born astrophysicist Sergei I. Gaposchkin in Germany; they married in 1934-- after which she was known as Payne-Gaposchkin -- and had three children. She became a pioneering astrophysicist in a largely male-dominated profession, and a role model for many other women scientists. She was the first to assert, against the conventional wisdom of the time, that stars are primarily made of hydrogen and helium. In collaboration with her husband, she undertook a systematic investigation of all known variable stars brighter than the tenth magnitude and published her results in 1938 as Variable Stars, which became the standard reference in the field. She spent her entire academic career at Harvard, rising from a technical assistant to become the first woman promoted to full professor from within the faculty at Harvard's Faculty of Arts and Sciences. Later, with her appointment to the Chair of the Department of Astronomy, she also became the first woman to head a department at Harvard. After her retirement from teaching in 1966, she continued her research at the Smithsonian Astrophysical Observatory. She authored or coauthored nine books and 351 papers between 1925 and 1979. Near the end of her life, she privately published her autobiography, The Dyer's Hand. She was the first recipient of the Annie Jump Cannon Award in Astronomy given annually by the American Astronomical Society.