The women who shaped astronomy
It's International Day of Women and Girls in Science and I want to show some love to the women who shaped astronomy.
The early astronomy pioneers
Hypatia of Alexandria (c. 350 – 415 was a Neoplatonist philosopher, and is widely regarded as the first female mathematician and astronomer.
Hypatia was one of the late Roman Empire's most prominent mathematicians, philosophers, and astronomers, and her murder sent a message to scholars in Alexandria, chilling scientific study. Glad we can't imagine what that would be like.
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A Chinese astronomer living during the Qing Dynasty, Wang Zhenyi (1768 – 1797) defied society's expectations of women, learning astronomy at home.
Wang Zhenyi was an early science communicator, describing celestial phenomena, explaining and demonstrating equinoxes and writing articles on lunar and solar eclipses.
The telescope trailblazers
While working alone, Caroline Herschel (1750 – 1848) detected three nebulae in 1783. In 1786, she became the first woman to discover a comet. Over the next 11 years, Herschel spotted seven more comets, including the periodic comet 35P/Herschel–Rigollet.
The self-taught Scottish astronomer Mary Somerville (1780 – 1872) played a vital role in the discovery of the planet Neptune. Along with Caroline Herschel, Somerville was elected as the first female Honorary Member of the Royal Astronomical Society. Note: they were the first female Honorary Members, the society wouldn't let women actually become members.
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Maria Mitchell (1818 – 1889) is best known as the first American professional female astronomer, and so probably needs no introduction. In 1847, Mitchell discovered comet C/1847 T1, earning her international recognition and a gold medal prize.
An advocate for education for girls and women, Mitchell travelled to Colorado with an all-female team of graduate researchers to observe 1878's solar eclipse.
The glimpses of history
Henrietta Swan Leavitt (1868 – 1921) pioneered stellar classification. Leavitt spent many years analysing photographic plates at Harvard College Observatory, discovering 2,400 new variable stars, including ‘Cepheid variables', whose luminosity (brightness) fluctuates in regular patterns.
Leavitt discovered a relationship between the star's period of variation and luminosity. Measuring how fast the stars flickered told astronomers how bright they were, and this became known as Leavitt's Law.
This giant leap for astronomy helped give astronomers the tool to measure the distances to stars and galaxies that were previously impossible with old methods.
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Cecilia Payne-Gaposchkin (1900 – 1979) discovered the stuff stars are made of, and revolutionised our understanding of the cosmos.
As a PhD candidate, Payne-Gaposchkin confirmed the theories of astrophysicist Meghnad Saha, and found that stars are mainly composed of hydrogen and helium.
A leading astronomer reviewing Payne-Gaposchkin's dissertation strongly discouraged her from publishing this outlandish idea, calling her work "spurious" in a published article. Payne-Gaposchkin downplayed it in her dissertation. That same astronomer later published research reaching the same conclusion and largely accepted credit for it. Aren’t you happy that never happens anymore?
Finding the invisible
Vera Rubin (1928 – 2016) provided compelling evidence for the existence of dark matter, defying accepted ideas about the universe.
Rubin's passion for astronomy began as a child, and she built a cardboard telescope (with the help of her engineer dad) to observe and track meteors. Rubin's PhD thesis showed that galaxies weren't randomly distributed through space but instead formed clusters and clumped together.
Rubin also found that some spiral galaxies should be flying apart from how quickly they rotated. This proved that a large amount of unseen mass was holding them together: dark matter.
Modern inspiration
Many scientists consider Ruby Payne-Scott (1912 – 1981) the first female radio astronomer.
Image credit: Peter Gavin Hall (Ruby Payne-Scott's son), CC BY-SA 3.0, via Wikimedia Commons
Payne-Scott's work has shaped our understanding of solar activity and its impact on Earth's atmosphere, and has helped lay the groundwork for understanding how these bursts affect communication systems, navigation, and even power grids on Earth.
During her career, Payne-Scott made significant contributions to solar astronomy, discovering three of the five categories of solar bursts.
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Nancy Grace Roman (1925 – 2018) was NASA's first Chief of Astronomy and is known to some as the "Mother of Hubble."
Roman proposed that a space – based telescope might detect planets orbiting other stars, and led NASA's orbiting astronomical observatories program. The program demonstrated the technologies necessary for the large space telescope.
Although known for her crucial role in planning the Hubble Space Telescope, Roman's contributions to astronomy include classifying stars by their chemical composition and motion through the galaxy.
Roman earned recognition from several women's organisations for her work advancing women in senior science management and was also one of four women featured in LEGO's 2017 Women of NASA set.
NASA's Nancy Grace Roman Space Telescope is scheduled for launch by May 2027.
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Jocelyn Bell Burnell (born 1943) discovered the first pulsar in 1967 while pursuing her PhD in astronomy at Cambridge uni.
Bell Burnell noticed a strange, rapidly pulsing signal in the radio telescope data she was studying. PSR B1919+21 is now known as a pulsar, a rapidly spinning neutron star that pulses a beam of radiowaves, like the regular beam of light from a lighthouse.
Image credit: Roger W Haworth , CC BY-SA 3.0, via Flickr
It was another 50 years before Bell Burnell won the Special Breakthrough Prize in Fundamental Physics for her pulsar discovery, and her work remains pivotal.
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Beth Brown (1969 – 2008) was a pioneering astrophysicist at NASA whose research focused on elliptical galaxies and black holes.
Brown found that many elliptical galaxies are incredibly bright in the X-ray part of the electromagnetic spectrum, suggesting the presence of gas heated to millions of degrees. She theorised the cause could be supernova explosions or supermassive black holes.
Brown was the first African-American woman to earn a PhD in astronomy from the University of Michigan. She was also a passionate educator, developing a popular astronomy course for beginners and appearing on TV to share her love of space science.