Biography of Cecilia Payne-Gaposchkin

Chelsea Chacko

Percival

Astronomy Period 5

April 19, 2014
                                            
                                     Cecilia Payne-Gaposchkin Biography

      Being a woman back in the 1900s was not very easy. The majority following and believing the ideal that every woman should be at home and taking care of children, looked down on women who dared venture from this. This, however, did not stop Cecilia Payne-Gaposchkin. Being the one to reveal that hydrogen was the most abundant element in the universe and known for her work with her husband on finding and measuring variable stars, Cecilia would prove that females could be just as passionate than men about their jobs.
      Born on May 10, 1900 in Wendover, England, Cecilia Helena Payne would find herself to be the eldest of three siblings under the care of her parents Edward John and Emma Helena Payne. Unfortunately, at the age of 4 her dad passed away, leaving her mother to influence her greatly in the classics which she loved throughout her life. In her early age, Cecilia came to know Latin and became fluent in French and German and had an interest in botany and algebra. She was also very influenced by the works of Isaac Newton, Thomas Huxley and Emmanuel Swedenborg.
      In 1919, Cecilia received a scholarship to attend Cambridge University where she pursued botany, chemistry and physics. While she was there, she became friends with a British astronomer named Stanley Eddington who introduced her to astronomy through his public lecture about the 1919 solar eclipse and Einstein's theory of relativity. He took her as a tutorial student and invited her to use the Cambridge Observatory's library which held all the latest astronomical journals. She completed her studies in 1923, however, at that time, women were not granted degrees in Cambridge so she received a Pickering Fellowship from Harvard, which had the world's largest archive of stellar spectra analyzing the , to work under Harlow Shapley who was the director of the Harvard Observatory.
     Her career at Harvard began in 1925 where Shapley became her thesis adviser. She would soon be the first awarded doctorate for her research at the Observatory, and the first to receive a doctorate in astronomy from Radcliffe. One of her passionate areas was astrophysics. The study of spectra actually made astrophysics. in1859, Gustav Kirchoff and Robert Bunsen found that each element has its own set of spectral lines. Comparing the stellar spectral lines with spectral lines of the chemical elements, astronomers found that heavy elements made a lot of the spectral lines and so they assumed that heavy elements made up the star completely. At Harvard, Annie Cannon sorted the spectra of over a hundred thousand stars into seven classes based on their different spectral characteristics. Many thought that the classes were due to the decreasing surface temperature of the stars but Cecilia, who studied quantum physics, understood that the patterns of the spectrum were due to the configuration of the electrons. She knew that at high temperatures electrons would be detached from the atom and create an ion, this was the first research done that used the Indian physicist Saha's recent theory of ionization. Cecilia began to measure the absorption lines in the stellar spectra and showed that the wide variation in it was due to the different ionization states of the atoms therefore due to the different surface temperatures of the stars, not from the different amount of elements. She calculated the amount of 18 elements in stars and revealed that the composition was almost the same in different types of stars. Cecilia also discovered that Sun, as well as many other stars are made up mostly of hydrogen and helium and that the heavier elements only made up for less than 2% of the mass of the star. This research became her doctorial thesis while she soon turned into a book called Stellar Atmospheres which was accepted by many astronomers. Cecilia taught people how to read the spectrum of any star to find its surface temperature. She explained that Cannon's ordering of the stellar spectral classes was based on a sequence of decreasing temperature and that she was able to calculate the temperatures. So now, the Hertzsprung-Russell diagram could be read and understood.
      Cecilia became the youngest scientist in the American Men of Science in 1926 but it was not until 1938, when she married a Russian-born astronomer Sergei Gaposchkin, that her work was recognized and received the title of Philips Astronomer. Getting married proved to be a great advantage for Cecilia. She did have three children, Edward, Katherine and Peter, Katherine being the one to pursue astronomy as well and help with her parents' research, however this did not keep her down; in fact, Cecilia continued to work even with having to take care of her children. Cecilia and Sergei both began to work together and became known for their research of variable stars, including pulsating variables, exploding stars, eclipsing binaries and rotating stars, as well as their research of the structure of a star. Both of them researched the structure of the Milky Way and the Magellanic Clouds, which are nearby galaxies; they discovered over two million estimates of variable stars' magnitudes in the Magellanic Clouds.
      Throughout the rest of her life, Cecilia continued to prove herself as an outstanding astronomer as she was the first woman to become a professor at Harvard and would soon head Harvard's Department of Astronomy from 1956 to 1960. While she was still a student at Cambridge in1923, she was elected to the Royal Astronomical Society and as well as the American Astronomical Society. In 1934, She received the Annie J. Cannon Prize due to her contributions to astronomy and in 1936 she became a member of the American Philosophical Society. Her recognition does not stop there as she doctorates of science from Wilson College, Smith College, Western College, Colby College and Women's Medical College of Philadelphia. Still winning many more awards and medals, Cecilia was also the first woman to receive the Henry Norris Russell Prize of the American Astronomical Society in 1976 and in 1977 a minor planet was named after her. Her contributions can still be seen in the 150 papers, monographs such as "The Stars of High Luminosity", and many books and textbooks she wrote such as Variable Stars, Stars in the Making and Stars and Clusters. Editing publication of the Harvard Observatory for 20 years and becoming an Emeritus Professor there, Cecilia would continue to write and research until her death, all proving that see was one of the greatest women astronomers in history.