Cecilia Payne-Coschkin
He challenged the foundations of astrophysics and launched those we still used today, at just 25 years old, when he had already discovered a fundamental truth about the universe.
It was 100 years that the young British Cecilia Payne He revolutionized our understanding of the stars, when he revealed in 1925 that they are composed predominantly by hydrogen and helium in their doctoral thesis, challenging scientific assumptions and thus launching the foundations of modern astrophysics at the age of 25.
Born in Wendover, England, Cecilia was early interested in science, recalls the. While studying at Cambridge University, he was inspired by the talk of astronomer Arthur Eddington about the 1919 solar eclipse, which confirmed Einstein’s theory of general relativity. It was Eddington who helped her orient herself to a career in astronomy, virtually nonexistent to date for women, which led her to move to the United States in 1923, when she accepted a Harlow Shapley postgraduate scholarship, director of the Harvard College Observatory.
In Harvard, the young astronoma had access to the world’s largest collection of star spectra (photographic sheets that capture the spread of rainbow-shaped stars). These spectra contain “absorption lines” that occur when the elements of a star’s atmosphere absorb light -specific wavelengths.
Scientists have long knew that each chemical element has a unique pattern of spectral lines, but many believed that the stars shared the elemental composition of the earth, with a predominance of heavy elements such as calcium and iron.
But Payne looked at the data differently, pushed by the emerging field of quantum physics. Realized that the appearance of spectral lines depended not only on the presence of elements, but also on their states of ionization How many electrons had been removed from atoms due to high temperatures.
Using recent theories developed by the Indian physicist MN Saha, concluded that variations in star spectra were largely due to temperature differences and not to the chemical composition.
In his doctoral thesis, he calculated the relative abundances of 18 stars and showed that hydrogen and helium were the vast majority of stellar mass, while the heavier elements represented less than 2% – a resounding revelation that contradicted what was working for right.
The results were classified as “clearly impossible” by the famous astronomer Henry Norris Russell, who reviewed his thesis and rejected it. Allegedly by pressure from the scientific community, Payne would even add a warning to her the thesis to say that her conclusions could not be exact – but quickly everything changed.
After an adaptation of the thesis, later investigations confirmed the discovery of the young British who had discovered a fundamental truth about the universe: Hydrogen is the most abundant element, not only on earth, but in all the cosmos.
Cecilia was not due to the discovery of the “heart” of the stars. He will also have contributed to the study of the variable stars in collaboration with the Russian astronomer Sergei Gaposchkin, with whom he would come to ties in 1934. But professionally, the fact that he was a woman still hurt her.
Throughout the 1930s, Cecilia served Harvard as a teacher, but without this title: she was a “technical assistant” in the official documents.
It was not until 1956 that Harvard appointed her full professor: she was the first woman to receive honor in the prestigious university. He later led the Astronomy Department and in 1976 he received the Henry Norris Russell award.
