Buzz
Cecilia Helena Payne-Gaposchkin (1900-1979) was a British-born astronomer who became a leading expert on variable stars—those whose brightness fluctuates—and the structure of our Milky Way Galaxy. She was among the first women to achieve the rank of professor at Harvard University and made history as the first woman to lead a department there.
Born on May 10, 1900, in Wendover, England, Cecilia Helena Payne entered Cambridge University in 1919. As one of the few women in the field of astronomy, Payne faced significant challenges, including ridicule from the famous scientist Ernest Rutherford, who mocked her as the sole female student in his lectures, provoking laughter from the male students. Despite these hardships, Payne’s unwavering passion for astronomy led to her success. She befriended Arthur Stanley Eddington, a young British astronomer who mentored her, and he later became a key figure in the study of stellar internal structure.
After completing her studies at Cambridge in 1923 and earning a B.A., Payne was faced with the reality that women could only obtain 'the Title of a Degree' at that time. Determined to pursue greater opportunities, she boarded the Caronia in 1923, heading to the United States. She soon enrolled at Radcliffe College, a women’s liberal arts school in Cambridge, Massachusetts, closely connected to Harvard University, where she continued her education.
Before Payne arrived in the U.S., Harlow Shapley, director of the Harvard College Observatory, had established an astronomy program to encourage women to pursue studies at the Observatory. Payne became the second student in this program after Adelaide Ames, who began in 1922. Payne dedicated herself to extensive work at the Observatory under Shapley’s guidance, earning her Ph.D. in astronomy from Radcliffe College in just two years. This marked the first doctorate awarded for research at the Harvard Observatory and also made her the first woman to earn a doctorate in astronomy from Radcliffe.
Her research focused on the atmospheres of stars. In 1925, she submitted her Ph.D. thesis, which later became the influential book 'Stellar Atmospheres,' to Radcliffe College. Otto Struve, a Ukrainian-born American astrophysicist, praised Payne’s dissertation as 'undoubtedly the most brilliant Ph.D. thesis ever written in astronomy.' Struve, renowned for his work on star spectra, made significant contributions to the study of stars.
Between 1927 and 1938, Payne served as Shapley’s technical assistant at the Harvard Observatory. Shapley often restricted Payne’s access to new electronic equipment and took measures to ensure her name was excluded from the Harvard and Radcliffe catalogs. It wasn’t until years later that she learned he had been paying her salary under the guise of 'equipment expenses.' In 1934, American astronomer Henry Norris Russell mentioned Payne as the most qualified person in the U.S. to succeed him at Princeton University, remarking 'alas, is a woman!' Despite Russell's influence in astrophysics, neither Harvard nor Princeton would have considered hiring a woman for a faculty position.
In 1934, Payne married Sergei Gaposchkin, a Russian-born Harvard astronomer and astrophysicist. Together, they collaborated on several research projects focusing on variable stars.
Payne-Gaposchkin’s contributions at the Harvard College Observatory went largely unrecognized and unofficial for many years. The courses she taught at Harvard were not listed in the catalog until 1945. She also witnessed the inequities faced by women in her field, as many performed the tedious calculations required for star location measurements and cataloging results from other scientists. Although some of these women had exceptional scientific potential, they were often discouraged or forced to leave their jobs due to marriage or dissatisfaction with low wages. In 1938, Payne-Gaposchkin was officially given the title of Phillips Astronomer.
After World War II, a new director took over the Harvard Observatory. In 1956, after a 31-year wait, Payne-Gaposchkin was finally appointed as a tenured professor of astronomy at Harvard, making her the first woman to achieve this status at the institution. She held the position until 1966. At the same time, she became the first female department chair at Harvard, leading the Department of Astronomy from 1956 to 1960. Having faced many challenges as a woman in a male-dominated field, Payne-Gaposchkin became a strong advocate for young female students pursuing careers in astronomy.
Payne-Gaposchkin made remarkable contributions to astronomy, particularly in identifying the chemical makeup of stars. She determined that hydrogen and helium are the most common elements in stars and, by extension, in the universe. In addition, she calculated the temperatures of stars. She gathered this knowledge through meticulous study and analysis of high-luminosity stars' spectra. In astronomy, luminosity refers to the total energy emitted by a star. This process involved observing light from distant stars, passing it through a prism, which broke it into a spectrum—a band of colors like a rainbow. At the red end of the spectrum, light has the longest wavelength, while violet represents the shortest wavelength. The spectrum emitted by stars contains dark and bright lines that reveal the elements in a star's outer layers and atmosphere. The astronomers compared these spectra from far-off galaxies to those of similar stars in our Milky Way galaxy.
The pioneering work of Payne-Gaposchkin and Gaposchkin on variable stars laid the essential groundwork for subsequent studies of these stars and their significance in understanding stellar structure. Variable stars are those whose brightness fluctuates over time. They can be classified into four main categories: (1) pulsating variables, (2) exploding stars (also known as cataclysmic variables), (3) eclipsing binaries, and (4) rotating stars.
Pulsating variables are stars that experience periodic changes in brightness as they expand and contract, with pulsations occurring every few days to up to 100 days. A notable type of pulsating variable is the Cepheid, named after the constellation Cepheus where the first was discovered. Payne-Gaposchkin and other astronomers were able to determine the distance to Cepheid variables by comparing their observed brightness to their inherent luminosities. The realization that other galaxies exist as separate systems, distinct from our Milky Way, was made possible through the observation of Cepheids.
Exploding stars release enormous amounts of energy in sudden outbursts, ejecting vast quantities of gas and dust into space. One form of exploding star that Payne-Gaposchkin researched is the nova (plural: novae). These stars can become thousands of times brighter than normal, and their brightness can persist for days or even years, before fading back to their dimmer state. Some novae undergo repeated explosions. Another type of exploding star, the supernova, shines millions of times brighter than a typical nova.
Eclipsing binaries consist of two stars that orbit one another. As they travel in their orbits, one star periodically blocks the light of the other, causing a temporary dip in the combined brightness observed from Earth. Eclipsing binaries are just one form of double star systems.
From 1966 to 1979, Payne-Gaposchkin served as an emeritus professor at Harvard, and from 1967 to 1979, she was a staff member at the Smithsonian Astrophysical Observatory. During her career, she authored numerous academic books and textbooks, including the popular titles *Stars in the Making* (1952) and *Stars and Clusters* (1979). For two decades, she also edited the publications of the Harvard Observatory, overseeing journals such as Bulletin, Circular, and Annals, in addition to books published under the Harvard Monographs series.
Payne-Gaposchkin received several honorary degrees from various institutions. While still a student at Cambridge, she was elected a member of the Royal Astronomical Society. She also became a member of the American Astronomical Society, American Philosophical Society, and the American Academy of Arts and Sciences. Her numerous accolades included a National Research Council Fellowship, the Graduate Medal from the Radcliffe Alumnae Association, the Annie Jump Cannon Award from the American Astronomical Society, the Henry Norris Russell Prize from the American Astronomical Society, the Award of Merit from Radcliffe College, and the Rittenhouse Medal from the Franklin Institute.
The Gaposchkins had three children: Edward, Katherine, and Peter. Katherine followed in her mother's footsteps and became an astronomer, collaborating with Cecilia on several papers. She also edited Cecilia's autobiography, *Cecilia Payne-Gaposchkin: An Autobiography and Other Recollections* (1984). Katherine passed away on December 7, 1979.
