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astronomy

Helen Sawyer Hogg

Helen Sawyer Hogg is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Helen Sawyer Hogg rather than just read about it. In short: Helen Battles Sawyer Hogg (August 1, 1905 – January 28, 1993) was an American-Canadian astronomer who pioneered research into globular clusters and variable stars. She was the first female president of several astronomical organizations and a scientist when many universities would not award scientific degrees to women.

Helen Sawyer Hogg — main illustration
Helen Sawyer Hogg — illustration

Key takeaways

  • Helen Sawyer Hogg belongs to astronomy; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Helen Sawyer Hogg to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Helen Sawyer Hogg from memory before moving on to harder problems.

Reference excerpt

Helen Battles Sawyer Hogg (August 1, 1905 – January 28, 1993) was an American-Canadian astronomer who pioneered research into globular clusters and variable stars. She was the first female president of several astronomical organizations and a scientist when many universities would not award scientific degrees to women. Her dedication to sharing astronomy with the wider public led to scientific advocacy and journalism, including columns in the Toronto Star ("With the Stars", 1951–81) and the Journal of the Royal Astronomical Society of Canada ("Out of Old Books", 1946–65). She was considered a "great scientist and a gracious person" over a career of sixty years.

Early life

Born in Lowell, Massachusetts, on August 1, 1905, Helen was the second daughter of banker Edward Everett Sawyer and former teacher Carrie Myra Sprague Sawyer. Academically gifted, Helen graduated from Lowell High School at the age of 15, but chose to stay for another year before leaving to attend Mount Holyoke College in 1922.

Education After graduating from high school, Hogg enrolled in Mount Holyoke College. Despite having nearly completed a chemistry degree, she changed her major from chemistry to astronomy after attending introductory astronomy classes with Dr. Anne Sewell Young in her junior year (1925). Dr. Sewell took her class to see the solar eclipse of January 24, 1925, and a year later Annie Jump Cannon, an astronomer working at Harvard University, came to visit Mount Holyoke. Hogg cited these experiences as defining moments that led to her career studying stars. In 1926 Hogg completed her undergraduate degree in astronomy, graduating magna cum laude. After graduating from Mount Holyoke, Hogg received a fellowship for graduate study at Harvard Observatory in the fall of 1926 with the help of Dr. Cannon. Once at Harvard, Hogg worked with Dr. Harlow Shapley, the director of the graduate program in astronomy. Following the expectations and work ethic of Dr. Shapley, Hogg worked hard, long hours measuring the size and brightness of globular clusters and published several papers. Hogg received her master's degree in 1928 and her doctoral degree in 1931, both from Radcliffe College, as Harvard refused to award graduate degrees in science to women at the time. For her advances in astronomy, Hogg received honorary doctoral degrees from six Canadian and U.S. Universities, including Mount Holyoke College and the University of Toronto.

Scientific works

While completing her doctoral degree, Hogg taught astronomy at Mount Holyoke and at Smith College. After graduation she moved to Victoria, British Columbia, where she began research at the Dominion Astrophysical Observatory. Hogg began taking photos of variable stars with the 72-inch reflecting telescope, cataloguing the cyclical changes in the brightness of the variable stars. At the Dominion Astrophysical Observatory, Hogg found 132 new variable stars in the globular cluster Messier 2. Hogg published this groundbreaking work in astronomical catalogues that are still used today. Notably, Hogg accomplished all of this as an unpaid volunteer assistant to her husband, as the Dominion Astrophysical Observatory would not offer her a job.

In 1935 Hogg moved to the University of Toronto, after her husband had received a job offer to work at the David Dunlap Observatory. For her first year there, Hogg continued her work photographing globular clusters, amassing thousands of photographs which she used to identify many thousands of variable stars. She published Catalogue of 1116 Variable Stars in Globular Clusters in 1939, the first of three catalogues she completed, with a fourth in the works at the time of her death. In addition to her work on variable stars in globular clusters, Hogg used the period-luminosity relationship of Cepheid variable stars (discovered by Henrietta Swan Leavitt in 1908) to enhance the understanding of the Milky Way Galaxy's age, size and structure. During the late 1930s, Hogg became one of the first astronomers to travel and work around the world to advance her research, as the globular clusters she was observing were best seen from the southern hemisphere. From 1939 to 1941, Hogg returned to America to serve as the president of the American Association of Variable Star Observers (1939–1941) and the acting chair of Mount Holyoke's astronomy department (1940–1941). Upon returning to the David Dunlap Observatory, she took on teaching duties at the University of Toronto, largely as a result of male staff being away due to World War II. Retaining her position after the men returned from war, Hogg advanced to assistant professor in 1951, associate professor in 1955, full professor in 1957, and professor emerita in 1976 upon her retirement. Over her research career Hogg published more than 200 papers, and was a leading authority in astronomy.

Scientific advocacy, awareness, and service

Not limiting herself to publishing her astronomical specialty of variable stars in globular clusters, Hogg published on the history of astronomy through her column "Out of Old Books", which was published in the Journal of the Royal Astronomical Society of Canada. She was also known for the 30 years she spent writing her weekly column "With the Stars", which was published in the Toronto Star. In addition, Hogg popularized astronomy with her book The Stars Belong to Everyone in 1976, an eight-show television series on Canadian educational television in 1970, and her role as founding president of the Canadian Astronomical Society. She also actively supported women to pursue science. In addition to her advocacy and awareness work, "Helen presided over several Canadian astronomical and scientific organizations", and "served on the board of directors of Bell Telephone Company of Canada from 1968 to 1978". She was also the director of the National Science Foundation's astronomy program, and in this position she "helped determine sites for the National Radio Astronomy Observatory and for Kitt Peak National Observatory" in 1955. In 1960, "she became the first woman president of the physical sciences section of the Royal Society of Canada", as well as "the first female president of the Royal Canadian Institute (1964–1965)".

Personal life

… excerpt ends here. Continue reading the full article.

Illustrations

Helen Sawyer Hogg illustration
Helen Sawyer Hogg: Lowell High School, where Helen graduated at 15 years old
Lowell High School, where Helen graduated at 15 years old
Helen Sawyer Hogg: Dominion Astrophysical Observatory c. 1900–1925
Dominion Astrophysical Observatory c. 1900–1925
Helen Sawyer Hogg: David Dunlap Observatory, 1935
David Dunlap Observatory, 1935
Helen Sawyer Hogg: Plaque in recognition of Dr. Helen Hogg at Canadian Museum of Science and Technology
Plaque in recognition of Dr. Helen Hogg at Canadian Museum of Science and Technology

Worked examples

Example 1 — a first encounter with Helen Sawyer Hogg

Start with the simplest possible case. Write down what Helen Sawyer Hogg claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Helen Sawyer Hogg before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Helen Sawyer Hogg ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Helen Sawyer Hogg

In research
Helen Sawyer Hogg appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Helen Sawyer Hogg in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Helen Sawyer Hogg is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1905 births, 1993 deaths, 20th-century American women academics, so understanding it makes those chapters shorter.
In everyday life
Look for Helen Sawyer Hogg outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Helen Sawyer Hogg in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Helen Sawyer Hogg means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Helen Sawyer Hogg out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Helen Sawyer Hogg in simple terms?

Helen Battles Sawyer Hogg (August 1, 1905 – January 28, 1993) was an American-Canadian astronomer who pioneered research into globular clusters and variable stars. She was the first female president of several astronomical organizations and a scientist when many universities would not award scienti…

Why does Helen Sawyer Hogg matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Helen Sawyer Hogg?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Helen Sawyer Hogg.

Tags

  • 1905 births
  • 1993 deaths
  • 20th-century American women academics
  • 20th-century American women scientists
  • 20th-century Canadian astronomers
  • 20th-century Canadian women scientists
  • Academic staff of the University of Toronto
  • American emigrants to Canada
  • American women astronomers
  • Burials at Lowell Cemetery (Lowell, Massachusetts)
  • Companions of the Order of Canada
  • Fellows of the Royal Society of Canada

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