This Astronomer Discovered What the Stars Were Made Of, And Few Believed Her Discovery

Cecilia Payne was in her early 20s when she figured out what the stars are made of. Both she and her groundbreaking findings were ahead of their time. Continuing the legacy of women working at the Harvard College Observatory, Payne charted the way for a generation of female astronomers to come.

This episode of the Lost Women of Science Shorts follows Payne’s journey of discovery, chronicles her drive and determination against all odds and takes you to the Harvard College Observatory itself to walk in her footsteps.

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EPISODE TRANSCRIPT

MARISSA MOSS:  She changes the way they see the stars themselves. 

KATIE HAFNER: Cecilia Payne figured out what stars are made of. 

MARISSA MOSS: It would be as if you said, “The earth really is round, not square.” It’s that kind of shift in people’s thinking.  

KATIE HAFNER: I’m Katie Hafner and this is Lost Women of Science Shorts. 

Cecilia Payne was 25 years old in 1925, and she just recently joined the Harvard Observatory. So perhaps not surprisingly, her findings were initially suspect. She was later proven right. 

The key that helped her to unlock the mystery? The observatory’s glass plate collection. Her fresh eyes allowed her to see on those plates what others had missed. 

The Harvard Observatory had started collecting glass plates back before Cecilia’s time. Until the advent of modern computers they were, for a hundred years, considered state-of-the-art. But analyzing the plates was labor intensive and that essential, but tedious work fell to women. What first started as astronomers’ wives, daughters, even a housemaid grew into a group of stellar women. Women like Williamina Fleming, Henrietta Swan Leavitt, and Annie Jump Cannon, each of whom more than deserves an episode in her own right.

For now though, let’s zoom in on Cecilia Payne, who brought a fresh perspective to the glass plates. Her observations upended scientific thought. 

Producer Lucy Evans takes us to Cambridge, Massachusetts. 

LUCY EVANS: Less than a mile from bustling Harvard Square on a hilltop sits the Harvard Observatory, founded in 1839 in what was once rural countryside, the better for astronomers to chart the night sky.

THOM BURNS: In Cecilia’s time, this hill was spotted with different domes that had telescopes and instruments in them. 

Unfortunately, a lot of that stuff fell into disrepair. It was wooden buildings, so now it is a parking lot. 

LUCY EVANS: That’s Thom Burns, curator of the Astronomical Glass Plate Collection that’s housed here, along with The Great Refractor, a telescope at the Harvard Observatory.

By the time Cecilia Payne arrived at the observatory in the fall of 1923, the collection of glass plates had grown astronomically, and she saw in them unlocked potential. But let’s go back to their inception. Because there would be no glass plates without the observatory’s telescopes. 

Burns pushes through the heavy metal door, and it takes a moment for our eyes to adjust to the cavernous room, multiple stories tall. 

THOM BURNS: So this is a great refractor. The thing that started this observatory.

LUCY EVANS: Installed in 1847, the great refractor with its fifteen-inch lens was, for twenty years, the largest telescope in the U.S. It’s still pretty imposing, sleek, and pointed to the sky. 

We can only imagine what it was like back in the mid-1800s to be in this echoey room viewing objects in the night sky that no man had ever seen before.

And it’s no accident, we’re using the word “man” since, for 50 years, access to the great refractor was limited strictly to men. 

DAVA SOBEL: So even at Harvard where women were regularly working in the observatory in the daytime, they didn’t really start doing nighttime observing until the mid-1890s. 

LUCY EVANS: That’s author Dava Sobel, whose book “The Glass Universe” tells the story of the women who worked at the Harvard Observatory.

DAVA SOBEL: Astronomy is a nighttime occupation, and there was something unseemly about having women involved in nighttime observations. Men and women together in the dark doing science, what a scandal. Doing science, right, right. 

LUCY EVANS: Instead, the women were relegated to hunkering down over the glass plates. Collected for more than a century, from 1885 all the way up to 1993, curator Thom Burns says there are over half a million glass plates in the collection. In all, they weigh about 165 tons, and they’re not small. Most are eight by 10 inches, the largest 14 by 17. 

THOM BURNS: Huge window pane size pieces of glass that hold thousands, if not millions of points of light that represent stars and the rest of our galaxy.

LUCY EVANS: And the collection holds more than just photographic negatives of the stars. Some were made with prisms that fan out the starlight, creating what’s known as stellar spectra. These plates are dense with information. Collecting these plates all started back in the mid-1800s when the Harvard Observatory saw the potential of pairing a telescope with a camera to make these glass plates.

THOM BURNS: Photography could allow astronomers to reference back in time. So if you wanted to know what a star looked like 10 years ago, the only way that you can see that is if you had the glass plates of it. 

LUCY EVANS: In 1877, Edward Pickering became Director of the Observatory, and over the next 40 years, he oversaw a huge expansion of the collection.

He had two and sometimes even three telescopes taking pictures throughout the night, which generated a whole lot of plates and a huge amount of data to sift through.

Pickering didn’t have enough staff to do it, but then he had an idea that would carve out a niche for women 

THOM BURNS: And he realized that women who are around him, like Williamina Fleming, who happened to be his housemaid, would be able to do that work.

DAVA SOBEL: And Pickering was pragmatic. 

I think you could get four women for the price of a man.  

So if we can get four pairs of eyes for the price of one pair of eyes, let’s do it. 

LUCY EVANS: Pickering’s successor, Harlow Shapley, continued the practice of low wages for women.

THOM BURNS: Shapley would actually record things in gal hours.  

LUCY EVANS: And in Shapley’s own autobiography, he speaks of this practice. He invented the term girl hours and said that some jobs even took kilo girl hours. He wrote, “That is how we got things done.”

Still, Pickering and Shapley’s treatment of women was considered better than most. At a time when the notion of women as astronomers was unthinkable at other institutions, Pickering and Shapley’s willingness to include them in their observatory arguably paved the way for women to emerge as stellar scientists.

DAVA SOBEL: I am a big booster of Pickering because I think he did so much for women. He nominated them for prizes. He set aside areas of research that they could do, even at home, even if they had families. He sought them out to be contributors to the scientific enterprise. 

LUCY EVANS: Still, the day-to-day tasks for most of the women working with the glass plates were repetitive and tedious, like human machines.

DAVA SOBEL: Before computers were machines, they were humans who were doing the math involved in interpreting astronomical observations. 

LUCY EVANS: When Cecilia arrived from England on a Pickering research fellowship in 1923, women computers had been hard at work at Harvard for about 40 years. Cecilia, a graduate student on a funded fellowship, was free to go where the science took her and to draw her own conclusions.

Make no mistake, other women had experienced some of this freedom too, but Cecilia also had the guts and determination to stand up and fight for herself, something that was true throughout her life. 

Born in 1900, the turn of the 20th century, Cecilia spent her childhood in the quaint village of Wendover in England.

Her father, a lawyer, died when she was four, leaving her mother to raise three children. When Cecilia was 12, they moved to London, and Cecilia was enrolled in a church school. 

On the top floor was a room set aside for the little science teaching they had. She wrote later in her autobiography quote, “I used to steal up there by myself, indeed I still do it in dreams, and sit conducting a little worship service of my own adoring the chemical elements”.

She insisted she learn advanced mathematics and German, necessary subjects to become a scientist, but no other girl in her school had ever needed or required those courses. 

And she was kicked out of that school at age 17. 

But her next school advanced her ambitions, and it was a scholarship that she won in 1919 that allowed her to go off to college, to Newnham, the women’s college at Cambridge University. 

There she was studying botany until she attended a lecture by astrophysicist Arthur Stanley Eddington that would change the course of her academic career and her life. Eddington had been able to prove that Einstein was right, that light does indeed bend when it passes near the sun. 

Here’s Dava Sobel. 

DAVA SOBEL: So when Eddington lectured about this at Cambridge, Cecilia Payne was completely transported. She didn’t sleep for three nights and she wrote down his entire lecture from memory. 

LUCY EVANS: Eddington had lit a fire. Afterwards, Cecilia went to see him about a possible future in astronomy. Dava Sobel says Eddington told Cecilia that he saw “no insuperable obstacles,” and Cecilia kept in touch with Eddington after that initial encounter.

So Cecilia starts taking classes in astronomy.  

MARISSA MOSS: She’s the only woman in these astronomy classes, and the men jeer at her.  

LUCY EVANS: That’s author Marissa Moss. She says Cecilia’s early college years were a tough time to be a female student in England.  

MARISSA MOSS: And this is a time when women can’t get degrees. They can go to classes. At least they can go to the library; the year before she started, they couldn’t even use the library. They had to have a man lend her the books, but she could actually go to the library. She could not check out books, but she could look at them there. So she was too poor to buy books. She was copying textbooks by hand.  

LUCY EVANS: So Cecilia would ride her bicycle into the lab chaperoned and in a full-length dress and hat as was expected for a woman to be seen in town.

Later in her autobiography, Cecilia recalled that the lab director, a Nobel Prize winner, opened every lecture by staring directly at her and saying, “Ladies and gentlemen.” 

Cecilia wrote later in her autobiography: 

CECILIA VOICE-OVER:  “All the boys regularly greeted this witticism with thunderous applause. And at every lecture I wished I could sink into the earth.”  

LUCY EVANS: When Cecilia Payne started at Newnham in 1919, the worldwide suffrage movement was in full swing. Just as American women were pressing for the right to vote, the women at Newnham were agitating for change too.  

MARISSA MOSS: In 1920, the women students were trying to push the faculty to give them actual degrees, because at this time if a woman graduated, she would get a piece of paper that would say, you have done the coursework and passed the exams. That means you would get a degree from Cambridge if you were a man, but you’re not, so you get this worthless piece of paper instead. And they wanted an actual college degree. This is an undergrad degree, not a graduate degree. They couldn’t get that. They couldn’t even get into graduate school, but you could not even get an undergraduate degree.

And when the women asked for it, the men were so outraged. The male students actually attacked the college. They tried to batter down the women’s college. They tried to put a battering ram into the gates. 

LUCY EVANS: But Cecilia did have one ally. His name was Leslie John Comrie, known as LJ. When Cecilia discovered that her Newnham College had its own observatory, she also found out that it was in need of repair and she needed help.

That’s where LJ came in. He helped Cecilia with the telescope, showed her how to use math to predict celestial movements, and explained computational astronomy. 

Back then, Cecilia was in her early twenties, and it was her friend LJ, who introduced her to the Harvard astronomer, Harlow Shapley when he came to deliver a lecture in London. 

DAVA SOBEL: She spoke to him immediately afterward about how much she wanted to come and work for him in America.

LUCY EVANS: That’s Dava Sobel again. 

DAVA SOBEL: She had guts, she had drive, and for a shy person, really managed to tap the right people at many points in her career. 

LUCY EVANS: It turns out there was a fellowship at Harvard, a one-year graduate research fellowship earmarked for a woman, but travel and living expenses? She was on her own.

She got some money from her college and entered into an obscure essay contest, writing about the Greek text of one of the gospels. It was something she knew nothing about. But her gamble that few people would enter paid off. No one else submitted and she won 50 pounds, which was enough, she said in her autobiography, for outfitting herself for her journey to the new world.

At the time, astronomy had been going through a change from mapping the heavens to actually understanding what was going on in the stars themselves. 

It was the shift from astronomy to astrophysics. 

A few years prior, Indian astronomer Meghnad Saha, had developed an equation linking a star’s temperature and pressure to its spectrum. But since he didn’t have the raw data to test it, it was so far just theory. 

Cecilia had just learned atomic physics and had at her fingertips a vast collection of stellar spectra at the Harvard Observatory. She recognized the extraordinary potential in these glass plates and was determined to crack the code of the spectra.

By all accounts, she threw herself into her work. Thom Burns is well versed on her duties. He takes out one glass plate in particular and points to century-old handwriting on it. 

THOM BURNS: The handwriting comes from different people at different times. You would actually write different notes as you discovered something on the plates.

LUCY EVANS: So it’s a collaboration of sorts, he says. Women who never met talking to each other across the decades. 

He leans in for a closer look and, almost reverentially, points to a scribble. 

THOM BURNS: And that’s Cecilia’s hand. 

LUCY EVANS: Thom Burns then walks us through her daily routine. Cecilia would select spectral plates to look at and take them to her office, but not by hand. These things were heavy. Thom Burns demonstrates one of the well-preserved carts designed to hold up to a hundred of the plates. 

It’s angled at one end so the plates don’t go crashing to the floor.

THOM BURNS: And you can wheel this around. You would have one on every four floors, and then you can take your stack of plates to the plates stack elevator. It’s a dumbwaiter that was designed to carry these heavy glass plates. And then she would follow the plates up the stairs.

LUCY EVANS: And then Cecilia would get to work poring over the plates with a magnifying glass and see, well, at first she didn’t quite know what she was seeing. The spectra just looked like what she called “tiny parallel smears”, and she couldn’t make sense of them. But then one day, something clicked. 

DAVA SOBEL: It turned out that they were showing that the stars were different temperatures.

LUCY EVANS: Cecilia then assigned a temperature range to each type of star that had been defined. 

DAVA SOBEL: And then she went further and she analyzed the actual elements in the stars. 

LUCY EVANS: And that, says Dava Sobel, brought about one of Cecilia Payne’s most shocking discoveries. At just 24 years old, what she figured out would change the understanding of the very nature of what the stars are made of. 

We’ll be right back.

DOMINIQUE JANEE: You’re listening to Lost Women of Science. I’m Associate Producer, Dominique Janee. If you’re enjoying this episode, you’ll find more on our website at lostwomenofscience.org. Our livelihood depends largely on the generosity of listeners like you. If you’d like to help us snatch important female scientists from the jaws of historical obscurity, just click the “donate” tab in the top right corner on our website. That’s lostwomenofscience.org.

DAVA SOBEL: It’s almost the way a picture suddenly reverses. So the things you thought were craters are actually hills. It’s a complete about-face. 

LUCY EVANS: Back in 1924, doctoral student Cecilia Payne, just 24 years old and working at the Harvard Observatory, made a discovery that challenged the fundamental scientific understanding of what the stars are made of.

She turned astronomy on its head. Here’s science writer Dava Sobel. 

DAVA SOBEL: Everything people were seeing in the stars were elements that were familiar on the earth. There was aluminum, there was iron, various things that seemed commonplace. And the thought was that the abundances would be similar to earthly abundances.

LUCY EVANS: In other words, the belief at the time was that the stars were made of the same stuff as earth in the same proportions. But the more Cecilia studied the glass plates, the more she wondered whether the current thinking was in fact wrong, because the hydrogen lines were far more pronounced than expected.

DAVA SOBEL: And that’s where she had her giant aha moment because hydrogen was about a million times more prevalent than anything else. 

LUCY EVANS: And the second most abundant is helium. So these two lightest of elements were suddenly the major components of the universe. 

MARISSA MOSS: Nobody can believe it, it just doesn’t compute. They can’t grasp that this could possibly be.

LUCY EVANS: That’s Cecilia Payne biographer, Marissa Moss. 

MARISSA MOSS: Eddington, who was her mentor and who she respected so much, when she sent him the paper, he said, “Oh, you mean hydrogen and helium on the surface?” And she says, “No, no, I mean the entire star. Inside. They’re entirely hydrogen and helium.” Nobody could quite conceive of that.

She changes the way they see the stars themselves. It really shifted. It would be as if you said, “The earth really is round, not square, not a table.” It’s that kind of shift in people’s thinking. I mean, it just reshifts the way you look at the universe. 

LUCY EVANS: But not everyone was on board with this shift.

Cecilia Payne’s earth-shattering discovery utterly undermined the status quo. Her boss, Harlow Shapley, sent her findings to the expert in stellar composition at the time, Princeton’s Henry Norris Russell, who told her that her results must be wrong. 

Cecilia knew Henry Norris Russell’s word could make or break a young scientist.

So, She made a decision she would later come to regret. She acquiesced and wrote in her thesis that her results were, “almost certainly not real.” But she left her data intact, perhaps hoping it would speak for itself. 

And it did finally earn Cecilia Payne her Ph.D. Although it was conferred by Harvard’s female equivalent, Radcliffe College, since Harvard was all male at the time.

It wasn’t until a few years after Cecilia’s Ph.D. that other research came out and Henry Norris Russell was able to draw the same conclusions utilizing a different process, and he was the one who authored the paper that was generally accepted by the rest of the predominantly male astronomers as the dogma moving forward.

Henry Norris Russell did briefly acknowledge Cecilia Payne’s discovery, but didn’t mention how he had disputed it initially. And it was Henry Norris Russell who widely got the credit, not Cecilia Payne. 

Cecilia wrote later in her autobiography:

CECILIA VOICE-OVER:  “I was to blame for not having pressed my point. I had given into authority when I believed I was right. I note it here as a warning to the young, if you are sure of your facts, you should defend your position.”

LUCY EVANS: After earning her Ph.D. in 1925, her fellowship funds stopped, so she needed a job and was hired back at Harvard by Shapley under the title of Technical Assistant. And this is where Cecilia learns the first lesson of the difference between a fellowship and a job that she’d now be paid at the end of the month, not the beginning.

DAVA SOBEL: She had to pawn her jewelry and her violin to get through her first month as a postdoctoral fellow at Harvard. 

LUCY EVANS: Cecilia wrote in her autobiography: 

CECILIA VOICE-OVER: “I was paid so little. I was ashamed to admit it to my relations in England, but I had the run of the Harvard plates. I could use the Harvard telescopes, and I had the library at my fingertips.”

LUCY EVANS: But once her freedom was no longer protected by the fellowship, Shapley could dictate her daily tasks. Rather than let her continue with the spectra, he instead directed her to the field of standard photometry. Still, she was devoted to her work and to Shapley. It was a dedication shared by his staff. 

They called him “DD”, for Dear Director. 

THOM BURNS: Dear Director. Yeah. He created a system of loyalty that went directly to him. 

LUCY EVANS: And though Cecilia taught many astronomy lectures, she wasn’t listed in the course catalog. 

Shapley did try to get her promoted, but pushback came from the highest office at Harvard. 

DAVA SOBEL: Harvard president Abbott Lowell, really didn’t want to see women on the faculty during his lifetime.

LUCY EVANS: Cecilia Payne had again hit a glass ceiling. Still, she remained at the Harvard Observatory until, at around age 33, tragedy struck. The untimely deaths of two dear friends in the span of a year, both in boating accidents, left Cecilia bereft. 

She took herself to Europe to take stock, visiting observatories and attending conferences perhaps to get her mind off things.

She traveled to Russia and then to Germany where, in 1933, she met astronomer Sergei Gaposchkin, age 35, with a Ph.D. in astronomy. He found himself as a Russian working in Germany, just as Hitler was taking power. 

DAVA SOBEL: He had lost his job. He was suspected of being a Russian spy in Germany, but he couldn’t go back to Russia because there he was considered a German spy.

LUCY EVANS: Cecilia turned to her boss, Harlow Shapley, who helped get a visa for Sergei, and gave him a job at the Harvard Observatory working directly with Cecilia. 

DAVA SOBEL: So they were together all the time and they fell in love and eloped. After just a few months they went off to New York and got married.

LUCY EVANS: Their colleagues were disapproving, in part because she was taller than he was, but they formed quite the pair and worked closely at the Harvard Observatory, dividing up the universe between them. 

Much of their work was on variable stars. 

DAVA SOBEL: So a variable star is one that changes its brightness over time in a regular cycle.

LUCY EVANS: Cecilia studied a whole range of variable stars. Stars like cepheids, which pulsate, getting bigger and smaller, brighter and dimmer. 

DAVA SOBEL: Her husband, Sergei Gaposchkin. He liked stars that changed their brightness because they were in some kind of relationship with other stars. 

LUCY EVANS: That’s when two stars revolve around each other.

Periodically, one star will eclipse the other, and that’s what makes their apparent brightness change. Could be a metaphor of sorts. 

The couple worked on parallel tracks, but with a clear common interest in all things celestial while their children ran through the maze that was the observatory complex, playing childhood games like hide-and-seek down in the well, holding the base of the giant refractor. 

Cecilia later wrote in her autobiography: 

CECILIA VOICE-OVER: “I had once pictured myself as a rebel against the feminine role. But in this, I was wrong. My rebellion was against being thought, and treated, as inferior”.

LUCY EVANS: She wrote that she never saw herself as a female astronomer. Of the title scientist or scholar she noted, “Neither of these words has a gender.” 

Harvard’s President Abbott Lowell, made good on his promise to keep women off the Harvard faculty while he was alive. And it wasn’t until two presidents later and the departure of Shapley that, in 1956, Cecilia was finally made a full professor, the first woman to be elevated to that position from within the university.

The promotion came with her first sizable pay increase, and a few months later, Cecilia Payne Gaposchkin became the first woman to chair a department at Harvard. She was 56 years old and kept the position for four years until 1960. 

By then, Cecilia had written or co-written nine books and 351 papers, and had made literally millions of observations of stars. 

But she is best known for that PhD dissertation she wrote back when she was in her early twenties, cracking the code of what the stars are made of.

Four decades later, it still held up. In 1962, the astronomer, Otto Struve pronounced Cecilia’s PhD doctoral dissertation, “The most brilliant thesis ever written in astronomy”. 

Here’s biographer Marissa Moss. 

MARISSA MOSS: Later in her life, this is how people summed up what she did. Physics Today said this about her, “She may have felt that she walked with giants. Now we recognize that she herself was one.” And another journal, this is The American Physical Society News said of her, “The giants, Copernicus, Newton, and Einstein. Each in his turn, brought a new view of the universe. Payne’s discovery of the cosmic abundance of the elements did no less”.

So there she is. She’s among the giants. 

LUCY EVANS: In 1976, three years before her death, she became the first woman awarded the Henry Norris Russell Prize. It’s named for the man who, decades earlier, had initially doubted her discovery. Near the end of her autobiography, Cecilia Payne Gaposchkin offers up this advice to young women:

CECILIA VOICE-OVER: “Do not undertake a scientific career in quest of fame or money. There are easier and better ways to reach them. Undertake it only if nothing else will satisfy you for nothing else is probably what you will receive. Your reward will be the widening of the horizon as you climb, and if you achieve that reward, you will ask no other”.

LUCY EVANS: That was a dramatization of Cecilia as read from her autobiography. Lost Woman of Science recently got hold of a digitally mastered recording of Cecilia herself being interviewed towards the end of her life. The audio quality is subpar, but here she is, a rare recording of Cecilia Payne Gaposchkin’s actual voice, recalling the painstaking work done by the women at the Harvard Observatory.  

CECILIA PAYNE GAPOSCHKIN: The stars had to be identified, they had to be marked on plates. There was a whole team of women who were working on it. And then the copy had to be written out. It was all written out by hand. I was there when they were still finishing it. 

LUCY EVANS: That was the voice of groundbreaking astronomer, Cecilia Payne-Gaposchkin, best known for discovering, in her twenties, what the stars are made of. She died in 1979 at the age of 79. 

For Lost Women of Science, I’m Lucy Evans. 

KATIE HAFNER: You’ve been listening to Lost Women of Science Shorts. Barbara Howard was the Senior Producer on this episode, Lucy Evans was Producer, and our Associate Producer was Dominique Janee. Our Sound Engineer was Hansdale Hsu. Thanks to my Co-Executive Producer Amy Scharf to Jeff DelViscio, and to Thom Burns and Lisa Bravada at the Harvard Astronomical Photographic Glass Plate Collection. Lost Women of Science is funded in part by Schmidt Futures and by The Alfred P. Sloan Foundation. This podcast is distributed by PRX and published in partnership with Scientific American. You can learn more at lostwomenofscience.org, and please think about clicking on that “donate” button to help us give female scientists the recognition they so richly deserve. I’m Katie Hafner. 

Further reading/listening

Episode Guests

• Dava Sobel is the author of the book “The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars”. 
• Marissa Moss is an author.

Thom Burns is the curator of the Astronomical Glass Plate Collection at the Harvard Observatory.