Margaret Lindsay Huggins

British astronomer

• Born: August 14, 1848
• Birthplace: Dublin, Ireland
• Died: May 24, 1915
• Place of death: Chelsea, London, England

Huggins engaged in a lifelong collaboration with her husband, with whom she did pioneering work in the field of astronomical spectroscopy, which they employed to study planets, stars, and nebulae. Together, they established the gaseous nature of the Orion nebula and published an important atlas of stellar spectra.

Early Life

Margaret Lindsay Murray was the second child of a solicitor, John Murray, and Helen Lindsay Murray, who were both of Scottish descent. Although her mother died when she was only eight, Margaret was apparently well cared for and became accomplished in music, writing, painting, and knowledge of antique furniture. She spent considerable time with her grandfather, who kindled her interest in astronomy by teaching her about the constellations, and she attended private school in Brighton, England. Little opportunity for higher education was available for women at the time, so she developed many of her skills on her own.

From about the age of ten, Margaret began a systematic study of sunspots. While she was in her early teens, she constructed a small telescope and used it to map sunspots. After reading an article in the magazine Good Word on the new science of spectroscopy—which identified elements by the unique patterns of lines in their spectra—she made her own prism spectroscope. She used her spectroscope to observe the dark lines in the solar spectrum that had been discovered by Joseph von Fraunhofer in 1814 and that were used in 1859 by Gustav Kirchhoff and Robert Bunsen to identify vaporized elements in the sun’s atmosphere. Margaret also developed a considerable skill in photography. As a result of these interests, she was introduced to the English amateur astronomer William Huggins, whom she married on September 8, 1875, at the Monkstown Parish Church near her family home. He was fifty-one, some twenty-four years her senior.

Life’s Work

After their marriage, Margaret and William Huggins became lifelong collaborators in the new field of spectroscopic astronomy. William already had an established reputation in astronomy, but Margaret brought new skills and energy to complement his efforts. William was from a wealthy family who lived at Tulse Hill in Lambeth, a suburb south of London. In about 1854, he sold the family business and built a private observatory in the garden of the family home.

Before he married Margaret, Huggins had been a lone observer, except for a brief collaboration with William Allen Miller during the early 1860’s. He had begun visual observations with a spectroscope, and Miller had assisted him in making photographs using an inconvenient wet process that yielded few results. Huggins and Miller demonstrated that stars produce continuous spectra with dark (absorption) lines like those of the sun. Some nebulae had similar dark-line spectra, indicating that they might consist of clusters of stars, but other nebulae were found to have bright (emission) lines that suggested they were gaseous. In 1868, Huggins made the important discovery that the lines emitted by moving sources, such as double stars, shifted toward the blue end of the spectrum when their sources were moving toward the solar system, and they shifted toward the red end of the spectrum when they were moving away. He correctly interpreted this as a Doppler shift that made it possible to measure the speed of the stars in the line of sight.

As the wife of William, Margaret Huggins contributed her skills in the newly developed use of dry photographic plates in addition to her intense interest in astronomical spectroscopy. Together they began a systematic program of investigating the chemical and physical properties of celestial sources using the new techniques of spectroscopy and photography. The Royal Society had provided a fifteen-inch refracting telescope and an eighteen-inch reflecting telescope for use at the Tulse Hill observatory. In 1876, Margaret assisted her husband in fitting the telescopes with photographic plates using the new dry-plate process, and they began their pioneering work in photographing astronomical spectra.

Although Margaret did not appear at first as coauthor of her husband’s published papers, he acknowledged her help in them. She immediately began making the entries in their laboratory notebooks, which clearly reveal her active involvement in all aspects of their work. She took particular interest in experimental design and in obtaining photographs. During 1876, she experimented with a variety of photographic plates, using both dry and gelatin plates with differing light sensitivities. For several years, she and her husband worked on obtaining long-exposure photographs of the planets, and Margaret gained special skill in guiding the telescope. They then fitted the eighteen-inch reflecting telescope with two special prisms for photographing the ultraviolet spectra of the stars. Before 1880, they published “The Photographic Spectra of Uranus, Saturn and Mars,” “Lines of Wolf-Rayet Stars in Cygnus,” “The Photographic Spectra of Stars,” and other papers in scientific journals.

During the 1880’s, Margaret worked with her husband to determine the nature of nebulae. In 1882, they became the first astronomers to obtain a photograph of the spectrum from the dim light of a nebula, the gaseous nebula in Orion. Such gaseous nebulae were characterized by bright green emission lines. These lines were close to several spectrum lines of known elements, especially magnesium, leading the astronomer Norman Lockyer to suggest that nebulae result from swarms of colliding meteors rich in magnesium. However, the Hugginses compared the green line of the nebula with the much brighter lines of burning magnesium and demonstrated that it did not coincide with any magnesium lines. They thought that the nebula’s green line might be produced by an unknown element, which they called nebulium; however, the line was later shown to be caused by the ionization of oxygen and nitrogen in conditions not attainable on earth. In 1889, this work was the subject of the first paper on which Margaret’s name appeared as coauthor, “On the Spectrum, Visible and Photographic, of the Great Nebula in Orion” in the Proceedings of the Royal Society.

During the 1890’s, Margaret continued to work with her husband on stellar spectra. Their work culminated in the publication of the Atlas of Representative Stellar Spectra in 1899. In 1906, she edited the addresses that her husband had given to the Royal Society during the five years he had been its president. In 1909, they published their collected Scientific Papers , which they edited jointly together. William, who was knighted in 1897, died on May 12, 1910. Margaret was working on his biography when she died five years later.

Significance

Margaret Huggins was one of the few women who actually practiced astronomy before the twentieth century. Only by collaborating with husbands or other family members were these women able to gain access to the observatory. She made significant contributions as a pioneer in astronomical applications of both spectroscopy and photography, developing important techniques in both fields. Her most important achievement was in obtaining with her husband the first photograph of the spectrum from the dim light of a nebula and differentiating it from the spectral lines of any known element.

Margaret’s work on stars and nebulae helped to identify the two main types of nebulae as either gaseous sources or clusters of stars. The latter discovery eventually led to the discovery of galaxies containing billions of stars. She and her husband demonstrated the possibilities of chemical and physical analysis of celestial objects and provided many examples of stellar spectra that could be further analyzed by others. These techniques and results led to the modern understanding of the evolution and structure of stars.

Bibliography

Becker, Barbara J. “Celestial Spectroscopy: Making Reality Fit the Myth.” Science 301 (September 5, 2003): 1332-22. This article places the work of Margaret Huggins and her husband in its historical context.

Belkora, Leila. Minding the Heavens: The Story of Our Discovery of the Milky Way. Bristol, England: Institute of Physics, 2003. A chapter on William Huggins includes a good discussion of Margaret’s role and contributions.

Pycior, Helena, Nancy Slack, and Pnina Abir-Am, eds. Creative Couples in Science. New Brunswick, N.J.: Rutgers University Press, 1996. This book on the contributions of women working with their husbands includes a chapter by Barbara J. Becker on Margaret Huggins documenting her important role as more than just an assistant to her husband.

Whiting, Sarah F. “Lady Huggins.” The Astrophysical Journal 42 (July, 1915): 1-3. Obituary written by an American friend and fellow astronomer.