While sailing from England to France one night at age 4, Dr. Burbidge looked skyward and saw, as if for the first time, a luminous patchwork of stars and planets. She went on to read books by astronomer James Jeans, a distant relative, and never looked back, devoting her life to a career in astronomy and astrophysics that revealed some of the farthest objects in the universe and upended a field long dominated by men.

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At a time when many women were expected to stay at home and cook, Dr. Burbidge wrote a kind of celestial cookbook, working with three co-authors to demonstrate how chemical elements such as carbon and oxygen are formed inside stars, where thermonuclear reactions produce heavier elements from lighter ones.

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Considered one of the most influential papers in astrophysics, the 1957 article formed the basis of a widely accepted theory for the origin of chemical elements, with a striking implication. As her collaborator William A. Fowler put it: “All of us are truly and literally a little bit of stardust.”

Dr. Burbidge was “a towering figure in the development of modern astrophysics” and “a trailblazer for gender equality in science,” said physicist George Fuller, director of the University of California at San Diego’s Center for Astrophysics and Space Sciences.

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The center was originally led by Dr. Burbidge, whose research formed a blueprint “for how the elements are cooked,” Fuller said, and established a framework for modern astrophysics altogether, “brokering this marriage between observational astronomy on the one hand and nuclear physics and elementary particle physics on the other.”

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Her work was all the more remarkable given that her research depended on the use of observatories that barred their doors to Dr. Burbidge in the 1940s, when she sought to leave her native England for larger telescopes in the United States.

Applying for a fellowship at the Mount Wilson Observatory near Los Angeles, Dr. Burbidge was rejected because she was a woman. The observatory later denied her request to use its telescope on the grounds that there was no women’s bathroom; undaunted, she used the telescope anyway after posing as an assistant to her husband, physicist Geoffrey Burbidge, who had turned toward astronomy while working as an assistant to his wife.

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“If frustrated in one’s endeavor by a stone wall or any kind of blockage, one must find a way around — another route towards one’s goal,” Dr. Burbidge wrote in a 1994 autobiographical essay, recalling her initial rejection at Mount Wilson. “This is advice I have given to many women facing similar situations. I tell them: Try it, it works.”

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Dr. Burbidge and her husband formed one of the most formidable husband-and-wife duos in modern science, writing numerous papers that combined Geoffrey’s focus on astronomical theory with Margaret’s observational skill. While he was large-framed and argumentative, chomping on cigars and criticizing the big-bang theory with anyone who would listen, she was diminutive and soft-spoken, reluctant to enter into public debates on the origin of the universe.

Nonetheless, she had “the classic iron fist under her velvet glove,” astronomer Joseph S. Miller once said. She shocked many of her peers when, in 1971, she rejected the Annie Jump Cannon Award, an American Astronomical Society prize awarded to outstanding female researchers.

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“It is high time that discrimination in favor of, as well as against, women in professional life be removed,” she wrote. Her refusal of the award spurred the creation of a working group on the status of women in astronomy, and came one year before she was named the first female director of Britain’s Royal Greenwich Observatory, a venerable 300-year-old institution once led by Edmond Halley.

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The position had traditionally come with the honorary title of Astronomer Royal. But for the first time, the distinction went to someone else, one of Dr. Burbidge’s male peers. Dr. Burbidge, who later said she was not sure whether the slight was a result of sexism or scientific politicking, resigned less than two years later, then became the first female president of the American Astronomical Society in 1976.

Delighting in complex mathematical calculations as well as the intricacies of optical astronomy, Dr. Burbidge studied the distance of stars, the rotations of far-off galaxies and the nature of quasars, or quasi-stellar objects, which electrified astronomers in the 1960s with their extreme brightness and radio-wave emissions. She went on to develop instruments used on the Hubble Space Telescope and was awarded the National Medal of Science by President Ronald Reagan in 1985.

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She was perhaps best known for her early work on the origin of elements, which culminated in the article “Synthesis of the Elements in Stars.” Published in the Reviews of Modern Physics, it became known as B2FH after the initials of its authors: the Burbidges, Fowler (who later received a share of the Nobel Prize in physics) and Fred Hoyle, who coined the term “big bang” but, like Geoffrey, favored an alternative theory known as the steady-state model of the universe.

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At times, Dr. Burbidge was also identified with the steady-state view, in which matter is continually being created, with the universe’s density more or less unchanged. (By contrast, the big-bang theory holds that the universe was created in a single, spectacular explosion, and has been expanding and growing less dense ever since.)

The Burbidges cited some of their quasar research in support of the steady-state model, which has fallen out of favor since the 1960s. But while some of Dr. Burbidge’s theories were disputed, her quasar observations contributed to major advances in the field, including the understanding “that every galaxy has a huge black hole in its center,” Fuller said.

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“I don’t like to think we’d ever come to the end of all that can be found out about the universe,” Dr. Burbidge once told the Los Angeles Times. “I’d like to think there will always be new surprises.”

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Eleanor Margaret Peachey was born in Davenport, England, on Aug. 12, 1919. Her father was a chemist who taught at the Manchester School of Technology, and her mother was one of two female students in his class.

Dr. Burbidge later recalled that one of her first scientific insights concerned her own conception: As a young girl recently acquainted with the “facts of life,” she suddenly realized she was born almost exactly nine months after the World War I armistice. “My excitement in telling my mother this deduction,” she wrote in her autobiographical essay, “was not greeted with enthusiasm nor with any further explanation.”

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She studied astronomy at University College London, where she received a bachelor’s degree in 1939 and a doctorate in 1943 while conducting spectroscopy experiments at the Mill Hill observatory, as German bombs fell nearby. In 1948 she married Geoffrey Burbidge, whom she met at a university lecture.

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Together they moved to the United States, where Dr. Burbidge performed research at the Yerkes Observatory in Wisconsin, McDonald Observatory in Texas, Harvard College Observatory in Massachusetts and California Institute of Technology before joining the faculty of the University of California at San Diego with her husband in 1962. They continued collaborating until his death in 2010.

In addition to her daughter, of San Francisco, Dr. Burbidge is survived by a grandson.

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In a phone interview, Sarah Burbidge recalled that while her mother was “thrust into this role of being a leading ‘woman astronomer,’ ” her “prime focus was just to be as good a scientist as she could be.”

“My views are anti-discrimination on all counts,” Dr. Burbidge told New Scientist magazine in 1972. “I don’t think what a person can do in life and what they want to do has to be conditioned by how they happen to be born: whether they’re black, white, yellow, or male or female. But I’m not a militant person — except in matters of astronomy.”