Unveiling the Secrets of the Stars
Cecilia Payne
Cecilia Payne was all of four years old when she faced the loss of her father, leaving her mother, Emma Leonora Helena, to single-handedly support the family. She commenced her education in Wendover, attending a private school overseen by Elizabeth Edwards. However, Emma was largely driven by the conservative ideas of the time and Cecilia’s prowess in sciences was not something she was prepared to explore, prioritizing her son, Humfry’s education instead, and moved to London when Cecilia was twelve, to further his prospects.
In her formative years in England, Cecilia faced what she described as "concentrated agony" while attempting to partake in the social dances popular among her peers. She endured taunts, such as being labeled "a girl who reads Plato for pleasure," a scornful remark uttered by one of her brother's acquaintances. Despite feeling disheartened by these experiences, Cecilia remained resolute in her pursuit of intellectual interests. She knew her mother would not spend money on her education, so she won a scholarship to Newnham College, Cambridge. Upon entering university, Cecilia swiftly realized her inclination toward studying a scientific discipline, yet remained uncertain about which specific field to pursue, not unlike many students at her age. She started her classes pursuing botany but changed to physics a year later.
She happened upon a public lecture by the astronomer Arthur Eddington, where he discussed his recent expedition to witness the 1919 solar eclipse, validating Einstein’s Theory of General Relativity. Reflecting on the experience later, she expressed her excitement. This lecture completely changed her perspective and with her unusually retentive memory, she was able to transcribe the lecture almost verbatim, when she returned to her room that day. This experience led her to the realization that her passion lay in the field of physics.
While studying physics, she faced discrimination at the hands of Ernest Rutherford, who was teaching there at the time. In her own words, she said that she was somewhat resented by Rutherford, due to a rule that prohibited women from occupying the same rows of seats as men. She often found herself sitting alone in the front row. This bothered Rutherford greatly, because he did not have a high opinion of women in research. He would invariably commence his lectures with pointed emphasis: "Ladies... and gentlemen”, which was greeted by uproar by her gentlemen peers. Nevertheless, she persisted.
At a later time, during an open night for the public at the Cambridge Observatory, she attended and posed numerous inquiries to the staff, prompting them to summon "The Professor." Taking advantage of the opportunity, she expressed her desire to pursue a career as an astronomer to Professor Eddington. He recommended several books for her to peruse, but she had already acquainted herself with them. Subsequently, Eddington became a mentor of sorts to her and extended an invitation for her to utilize the Observatory's library, granting her access to the latest astronomical journals. This small but significant gesture broadened her horizons and introduced her to the realm of astronomical research. Even in her later years, she continued to regard Eddington as the greatest man she had the privilege to know. However, Eddington was clear to her regarding the fact that she would not have a great career in England.
During her final undergraduate year in 1922–23, and under the active encouragement of L J Comrie, who later assumed the role of superintendent of the Nautical Almanac Office, she contemplated the idea of pursuing astronomy studies in the United States. It so happened that Harlow Shapley, with a background that included journalism, had recently assumed the directorship of Harvard College Observatory. During his visit to Britain for the centenary celebrations of the Royal Astronomical Society in May 1922, Comrie introduced Cecilia to Shapley. She found him to be remarkably supportive and approachable, a stark contrast to the limited encouragement she had received at Cambridge regarding applications for research assistantships or study grants.
In 1923, Payne concluded her studies at Cambridge. Given the restrictions of that era, women could only receive "the Title of a Degree," so Cecilia was not officially awarded a degree. She then embarked on a journey to the United States to explore broader opportunities. Subsequently, she commenced her studies at Radcliffe College, a private liberal arts college for women located in Cambridge, Massachusetts, which maintained close affiliations with Harvard University. Her decision marked the beginning of a remarkable career that would revolutionize the field of astronomy. At Harvard, she encountered the brilliant minds of the Harvard Observatory, including renowned astronomers like Harlow Shapley and Annie Jump Cannon, who would become influential mentors in her life.
Under the guidance of Anne Cannon, Payne-Gaposchkin delved into the study of stellar spectra, laying the groundwork for her groundbreaking doctoral thesis. Her research focused on analyzing the spectral characteristics of stars, particularly their temperatures and compositions. Harlow Shapley often expressed the sentiment that one could not obtain a Ph.D. without enduring significant hardship throughout the process. As Cecilia Payne approached the conclusion of her doctoral project on stellar spectra, she too faced months (that added up to a year) of complete bewilderment regarding her research. This might serve as an encouragement to all the current doctoral scholars who are exhausted by their research seemingly going nowhere.
Around 1925, Cecilia attained her Ph.D. in astronomy from Radcliffe College, despite all her misgivings. Her doctoral dissertation, titled "Stellar Atmospheres, A Contribution to the Observational Study of High Temperature in the Reversing Layers of Stars”, focused on quantifying the absorption lines found in stellar spectra and was lauded by Ukranian born American astronomer Otto Strauve as "the most remarkable Ph.D. thesis ever penned in astronomy." The published version spans over 200 pages, inclusive of five appendices, and is structured into three sections: The Physical Groundwork, Theory of Thermal Ionisation, and Additional Deductions from Ionisation Theory.
Payne possessed a superior understanding of atomic spectra compared to most astronomers of her time. Additionally, she was familiar with the 1920 research conducted by Indian physicist Meghnad Saha on the thermal ionization of atoms. Saha had demonstrated the application of an equilibrium equation from physical chemistry to establish connections between the ratio of excited states to ground states, the fraction of ionized states, and various properties of stellar atmospheres such as temperature, electron concentration, and ionization potential. Payne had the opportunity to meet Saha during his visit to Harvard, coinciding with the rising recognition of his work among astronomers, who were starting to use the Saha equation in their research.
Completing her thesis on January 1, 1925, Payne validated the perspectives of Henry Norris Russell and Henry Augustus Rowland regarding the prevalence of heavier elements in stellar atmospheres. Subsequently, she utilized Saha's equations to analyze the absorption of the Balmer series in hydrogen, originating from atoms in the first excited state. She astutely realized that in the Sun's atmosphere at 5700 K, only a minute fraction of hydrogen atoms—approximately one in 200 million—exist in this excited state, resulting in a substantial underrepresentation of hydrogen quantity through Balmer absorption. This reasoning extended to helium as well. Payne's findings were consistent across various stars, leading her to the groundbreaking conclusion that hydrogen and helium, contrary to Earth's composition, are the predominant elements in the Sun and stars.
Despite Payne's significant discovery, Henry Norris Russell vehemently opposed her conclusion and persuaded her to exclude it from her thesis. Nonetheless, current accepted values for the mass fraction of elements in the Milky Way Galaxy corroborate Payne's findings, indicating approximately 74% hydrogen, and 24% helium, with the remaining elements accounting for only 2%. This discovery of the true cosmic abundance of elements revolutionized our understanding of the universe. Just as Copernicus, Newton, and Einstein each brought forth a new perspective on the cosmos, Payne's revelation of the cosmic abundance of elements marked a profound shift in our understanding of the universe.
Upon attaining her doctorate, Cecilia Payne deliberated over various options but ultimately chose to remain at Harvard. However, due to institutional barriers prohibiting the advancement of women to professorial positions at Harvard during that era, she found herself relegated to lower-ranking roles with modest pay for several years. Despite these challenges, Payne authored several notable books, among them "The Stars of High Luminosity" in 1930, "Variable Stars" in 1938, and "Variable Stars and Galactic Structure" in 1954.
Between 1927 and 1938, she served as Shapley’s technical assistant at the Harvard Observatory. Payne frequently encountered obstacles under Shapley's supervision, as he restricted her access to new electronic equipment and deliberately omitted her name from the Harvard or Radcliffe catalogs. It was only years later that she discovered he had been paying her salary under "equipment expenses" because his hands had been largely tied by the regulations of university of that era. In 1934, American astronomer Henry Norris Russell mentioned Payne in his writings, lamenting that the most qualified candidate in the United States to succeed him at Princeton University was, regrettably, a woman. Russell wielded significant influence in advancing theoretical astrophysics in the U.S. and served as director of the observatory at Princeton University from 1912 to 1947. Both Harvard and Princeton were institutions that traditionally overlooked women for faculty positions.
In 1934, Payne embarked on a visit to the observatory in Leningrad amidst heightened tensions between the Soviet Union and Germany, coupled with austere living conditions and an air of suspicion towards foreigners. Undeterred, she proceeded to Germany, where similar tensions prevailed, and there she encountered a young Russian astronomer named Sergei Gaposchkin. They married in 1934 after she helped him get a visa to America, and she became Cecilia Payne-Gaposchkin, subsequently becoming the mother to three children.
In their professional endeavors, the Gaposchkins worked diligently together, conducting comprehensive studies on variable stars, notably including Magellanic Cloud cepheids. They authored numerous books individually or collaboratively, and also compiled annual lists of published papers. A thorough examination of authentic biographies revealed a total of 351 papers published between 1925 and 1979, including five in 1979 alone, along with nine books authored or co-authored by Sergei Gaposchkin. The observations and analyses conducted by Payne-Gaposchkin and Gaposchkin served as the cornerstone for subsequent research on variable stars and their significance in deciphering stellar structure. Variable stars, characterized by fluctuations in brightness, encompass four primary types: pulsating variables, exploding stars (referred to as cataclysmic variables), eclipsing binaries, and rotating stars.
Payne-Gaposchkin's contributions at Harvard College Observatory went unrecognized and unacknowledged. It wasn't until 1945 that any of the courses she taught at Harvard appeared in the official catalog. Furthermore, she witnessed the disparity in gender roles within her field, with women predominantly relegated to tedious computational tasks in the observatory's back rooms. Despite possessing considerable scientific aptitude, many of these women had encountered discouragement along their career paths. Moreover, they risked losing their employment if they chose to marry or voiced grievances about their meager salaries. Shapley had endeavored to enhance Payne’s status, and in 1938, she was granted the designation of "Astronomer." At Payne's behest, her title was subsequently modified to Phillips Astronomer, an endowed role that would elevate her to the status of an "officer of the university." To obtain approval for her new title, Shapley assured the university that conferring this position upon Payne-Gaposchkin would not equate her to a professor. However, privately, he advocated for the position to eventually transition into a formal professorship, specifically as the "Phillips Professor of Astronomy."
Following her doctoral studies, Payne delved into the examination of highly luminous stars to unravel the intricacies of the Milky Way's structure. Subsequently, she conducted a comprehensive survey of stars brighter than the tenth magnitude. Her focus then shifted to the study of variable stars, during which she amassed over 1,250,000 observations with the assistance of her team. Expanding her research to include the Magellanic Clouds, Payne amassed an additional 2,000,000 observations of variable stars. These extensive datasets were instrumental in elucidating the trajectories of stellar evolution. Payne disseminated her findings in her second publication, "Stars of High Luminosity," released in 1930.
After a 31-year-long wait, Payne-Gaposchkin was finally bestowed with the title of tenured professor of astronomy at Harvard in 1956 when Donald Menzel became the director of the observatory, a position she retained until 1966. This appointment marked her as the inaugural woman to attain full tenure at Harvard. Concurrently, she assumed the role of department chair, becoming the first woman to lead Harvard’s Department of Astronomy from 1956 to 1960. Payne-Gaposchkin's personal challenges as a woman in a predominantly male-dominated field fueled her advocacy for young female students, making her a staunch supporter of their aspirations.
Between 1966 and 1979, Payne-Gaposchkin held the position of emeritus professor at Harvard University. Additionally, from 1967 to 1979, she served as a staff member at the Smithsonian Astrophysical Observatory. Throughout her career, she authored numerous academic books and textbooks, alongside popular works like "Stars in the Making" (1952) and "Stars and Clusters" (1979). Over two decades, she played a pivotal role in editing Harvard Observatory's publications, which included journals such as Bulletin, Circular, and Annals, as well as books published under the Harvard Monographs series.
In addition to her groundbreaking research, Payne-Gaposchkin played a pivotal role in advocating for women in science. Throughout her career, she faced discrimination and barriers due to her gender, yet she remained steadfast in her commitment to advancing the cause of women in academia. As a trailblazer in a male-dominated field, she inspired generations of female scientists to pursue their passions and break down barriers. Her legacy extends far beyond her scientific contributions. She was a passionate educator who dedicated herself to sharing her knowledge and enthusiasm for astronomy with others. As a professor at Harvard University, she mentored countless students, instilling in them a love for science and a dedication to excellence.
Payne-Gaposchkin received honorary degrees from several colleges. She was elected a member of the Royal Astronomical Society while still a student at Cambridge. Additionally, she became a member of prestigious organizations such as the American Astronomical Society, American Philosophical Society, and American Academy of Arts and Sciences. Throughout her career, she was recognized with accolades including the National Research Council Fellowship, the Graduate Medal of 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. She is also the inspiration behind the plays, "Stargazer: The Cecilia Payne Story" and "The Women Who Mapped the Stars."
Cecilia Payne’s life and work continue to inspire astronomers and scientists around the world. Her pioneering research and unwavering determination have left an indelible mark on the field of astrophysics, shaping our understanding of the cosmos and inspiring future generations to reach for the stars. Her personal life exemplified resilience and fortitude in the face of adversity. Despite experiencing personal tragedies and professional challenges, she remained steadfast in her pursuit of knowledge and scientific inquiry. Her indomitable spirit serves as an inspiration to all who aspire to overcome obstacles and achieve greatness.
Throughout the early 1920s and beyond, Cecilia Payne-Gaposchkin faced the pervasive challenges of gender bias, enduring a career marked by being overlooked and undervalued. Despite her remarkable accuracy and extensive knowledge surpassing many of her contemporaries, her discoveries were met with skepticism and subjected to rigorous scrutiny. She grappled with the constraints of undefined and inadequately compensated roles for much of her professional life. As we reflect on her remarkable legacy, we celebrate not only her scientific achievements but also her enduring legacy as a trailblazer, educator, and advocate for equality in science.
References:
Popova, M. (2017, July 26). Advice to the Young from Pioneering Astrophysicist Cecilia Payne-Gaposchkin, Who Discovered the Composition of the Universe. The Marginalian. https://www.themarginalian.org/2017/07/26/cecilia-payne-gaposchkin-autobiography-advice/
Wayman, P. A. (2002). Cecilia Payne-Gaposchkin: astronomer extraordinaire. Astronomy and Geophysics, 43(1), 1.27–1.29. https://doi.org/10.1046/j.1468-4004.2002.43127.x
Moore, D. (2020). What stars are made of: the life of Cecilia Payne-Gaposchkin. Cambridge, Massachusetts, Harvard University Press.
Payne-Gaposchkin, C., & Haramundanis, K. (1996). Cecilia Payne-Gaposchkin : an autobiography and other recollections. Cambridge University Press.
