Education and Early Career

Helen Sawyer was born in Lowell, Massachusetts, to Edward Everett Sawyer, a banker, and Carrie Sprague Sawyer. She attended public elementary and secondary schools in the city before enrolling at Mount Holyoke College, where she achieved a BA in 1926, and later Radcliffe College, where she secured both her MA (1928) and PhD (1931) in astronomy. At this time, Radcliffe was a sister college to Harvard University, and Sawyer studied under renowned astronomer Harlow Shapley at the Harvard College Observatory. Her doctoral research focussed on variable stars (stars with fluctuating brightness) and globular star clusters (sphere-shaped formations of stars and the oldest parts of our galaxy). While pursuing her studies, she met Canadian Harvard astronomy graduate student Frank Scott Hogg, and they married in 1930.

Early in her university career, Helen Sawyer Hogg wanted to become a chemist. This changed when her astronomy professor at Mount Holyoke College took her class on a field trip to witness a total solar eclipse on 24 January 1925. Sawyer Hogg later recalled, “the glory of the spectacle seems to have tied me to astronomy for life, despite my horribly cold feet as we stood almost knee deep in the snow.”

In 1931, the couple moved to Victoria, British Columbia, where Frank was hired to work at the Dominion Astrophysical Observatory (see Observatory). During the Great Depression, according to their daughter, Sally MacDonald, public institutions were not allowed to hire both husband and wife, but Helen received permission to use the facility’s large telescope to carry out unpaid astronomical research on star clusters. In addition to the restriction on hiring spouses, few women were allowed access to the observatory, since it was deemed inappropriate to work alone with men at night. Ironically, the same factor that may have prevented Sawyer Hogg from being hired — her husband’s employment at the observatory — thus allowed her to use the facility for research.

In 1935, Frank was hired by the Department of Astronomy at the University of Toronto, and Helen was able to perform research on a volunteer basis. The two scholars carried out most of their studies at the David Dunlap Observatory in Richmond Hill, just north of Toronto, with Frank serving as the observatory director from 1946 until his death in 1951. (Helen was later married to retired English professor F. E. L. Priestly from 1985 until his death in 1988.)

Career Highlights

In 1936, Sawyer Hogg became officially affiliated with the University of Toronto Department of Astronomy as a research assistant. By 1941, the departure of many men on faculty for the Second World War had created opportunities for women, and she became a lecturer. Sawyer Hogg became a full professor in 1957 and was named professor emeritus upon her retirement in 1976.

In her dedicated, decades-long pursuit of interstellar discovery, Sawyer Hogg used the David Dunlap Observatory’s immense telescope to take thousands of photographs of the Milky Way, the galaxy that contains Earth’s solar system. Through methodical research and analysis, she produced more than 200 scholarly reports and articles, including A Catalogue of 1116 Variable Stars in Globular Star Clusters in 1939. Given this work’s importance to the astronomical community, updated editions were printed in 1955 and 1973.

Beyond the academic realm, she popularized the field for a broad audience by giving lectures that were broadcast on the radio, hosting an eight-episode television show and writing a weekly column, With the Stars, for the Toronto Star from 1951 to 1981. In 1976, she published her most famous book, The Stars Belong to Everyone: How to Enjoy Astronomy.

Sawyer Hogg’s prominence as an astronomer led to directorial positions in many scientific and astronomical organizations. She was program director for Astronomy at the US National Science Foundation in 1955–56 and president of the Royal Astronomical Society of Canada from 1957 to 1959. Named a Fellow of the Royal Society of Canada in 1946, she served as president of its Physical Sciences section in 1960–61. In 1964, she was named the first female president of the Royal Canadian Institute, the nation’s oldest scientific society. She was also the founder and inaugural president of the Canadian Astronomical Society in 1971. Sawyer Hogg’s success extended into business: she was one of the first two women appointed to the Bell Telephone Company of Canada’s board of directors, a position she held from 1968 to 1978.


As an internationally recognized leader in the field of globular star clusters, Sawyer Hogg significantly advanced astronomers’ understanding of the location and age of stars as well as the origins and evolution of our galaxy. She also contributed greatly to the Canadian public’s understanding of astronomy and inspired women to enter scientific professions. Several women she mentored continued her work on variable stars in globular star clusters. Christine Clement, professor emeritus of astronomy at the University of Toronto, praised her former advisor for earning respect in her field “at a time when women were often ridiculed for studying science.” Having raised three children while advancing her career — even after the death of her husband at age 46 — Sawyer Hogg also served as an inspiration to women astronomers working to balance professional and family commitments.

Discovered in 1980, Asteroid #2917 was officially named Sawyer-Hogg in 1984. The National Museum of Science and Technology (now the Canada Science and Technology Museum) named its observatory in her honour in 1989 and the University of Toronto’s Southern Observatory, in Chile, named its telescope the Helen Sawyer Hogg Telescope in 1992. When this observatory closed in 1997, the telescope was moved to Argentina, but its name was retained.

Honours and Awards

Helen Sawyer Hogg has been recognized publicly with numerous awards and accolades. She won the Annie J. Cannon Prize from the American Astronomical Society (1950) and was the first Canadian and the second woman to win the Rittenhouse Silver Medal (1967). The Medal of Service from the Order of Canada (1968) followed, along with the Klumpke-Roberts Award from the Astronomical Society of the Pacific (1983) and the Sandford Fleming Medal from the Royal Canadian Institute (1985). Sawyer Hogg was promoted within the Order of Canada to the rank of Companion in 1976. In 2004, she was posthumously inducted into the Canadian Science and Engineering Hall of Fame.