Helen Sawyer Hogg (1905-1993)


Click here for more information about the Helen Sawyer Hogg Visitorship.

Helen Sawyer Hogg was a renowned Canadian astronomer. She was born and educated in New England, but after she received her PhD from Radcliffe College in 1931, she moved to Canada with her husband Frank Hogg (1904-1951), also an astronomer. From 1931 to 1935, they worked at the Dominion Astrophysical Observatory in Victoria, British Columbia. Then in 1935, the family relocated to Richmond Hill, Ontario, to the newly opened David Dunlap Observatory. She remained in Richmond Hill for the rest of her life.

Professor Hogg was a world expert on globular clusters and her catalogues of variable stars in globular clusters have been widely cited in the astronomical literature. She was also a skilled administrator. Throughout her career, she served as president of many scientific organizations. When the Canadian Astronomical Society formed in 1971, she was the founding president. In addition, she was well known for her writings. For 30 years, she wrote a popular weekly column on astronomy in the Toronto Star. Her book, The Stars Belong to Everyone: How to Enjoy Astronomy, was published in 1976.

Helen Sawyer Hogg’s achievements were recognized by numerous honorary degrees, awards, and medals, including appointment as a Companion of the Order of Canada in 1976.

Portrait of Chant


Portrait of Chant


Professor Hogg's career highlights
Lowell, Massachusetts, August 1, 1905
Lowell Public Schools
Mount Holyoke College A.B. (Magna cum Laude) 1926
Radcliffe College A.M. 1928
Radcliffe College Ph.D. 1931
Dominion Astrophysical Observatory, Victoria, B. C. 1931-1935
    Unpaid volunteer
David Dunlap Observatory, University of Toronto 1935-
    Unpaid Volunteer 1935
    First appointment 1936
    Professor 1957-1974
    Research Professor 1974-1976
    Professor Emeritus 1976
Other Important Positions
    Mount Holyoke College – Acting Chairman, Astronomy Department 1940-1941
    United States National Science Foundation – Program Director for Astronomy 1955-1956
Took thousands of photographs of globular clusters to search for and study variable stars. Published more than 200 papers on this work. Produced bibliographies and catalogues of variable stars in globular clusters, valuable resources that were widely cited by researchers interested in the subject.
Taught elementary astronomy for non-science students for almost thirty years.
Wrote column With the Stars in the Toronto Star for 30 years.
Popular book on astronomy The Stars Belong to Everyone published by Doubleday Canada in 1976.
Published several dozen articles on historical astronomy in the Journal of the Royal Astronomical Society of Canada.
President American Association of Variable Star Observers 1939-1941
President International Astronomical Union
Subcommission, Variable Stars in Star Clusters
President Royal Astronomical Society of Canada 1957-1959
President Physical Sciences section, Royal Society of Canada 1960-1961
President Royal Canadian Institute 1964
Councillor American Astronomical Society 1965-1968
Director Bell Telephone Company of Canada
(One of first two women)
First President Canadian Astronomical Society 1971-1972
Honorary President Toronto Centre, Royal Astronomical Society of Canada 1972-1977
Honorary President Royal Astronomical Society of Canada 1977-1981
Fellow Royal Society of Canada
First woman in Physical Sciences Section
D.Sc. Mount Holyoke 1958
D.Sc. University of Waterloo 1962
D.Sc. McMaster University 1976
D.Sc. University of Toronto 1977
D. Litt. Saint Mary’s University 1981
D.Sc. University of Lethbridge 1985
Annie J. Cannon Prize American Astronomical Society 1950
Rittenhouse Medal Rittenhouse Astronomical Society, Philadelphia 1967
Service Award Medal Royal Astronomical Society of Canada 1967
Radcliffe Graduate Achievement Medal Radcliffe College 1967
Centennial Medal Canada 1967
Medal of Service Order of Canada 1968
Companion Order of Canada 1976
Order of Merit City of Toronto 1985
Sandford Fleming Medal Royal Canadian Institute 1985
IAU Colloquium No. 21, Variable Stars in Globular Clusters and in Related Systems, held in her honour on the 29th to 31st of August 1972 in Toronto
Asteroid 2917 named Sawyer Hogg, 1984
Helen Sawyer Hogg Lectures, annual public lectures sponsored by the Canadian Astronomical Society and the Royal Astronomical Society of Canada
Helen Sawyer Hogg Observatory, National Museum of Science and Technology in Ottawa, dedicated 1989
First scientist profiled in the Scientists and Inventors series of books for elementary school children: Helen Sawyer Hogg – A Lifetime of Stargazing by Michael Webb published by Copp Clark Pitman, 1991
Helen Sawyer Hogg Telescope, University of Toronto Southern Observatory, dedicated 1992
Honorary Life Memberships in the Ontario Field Naturalists, the Royal Canadian Institute, the University Women’s Club of Toronto, the Royal Astronomical Society of Canada, and Science North, Sudbury
After her death in 1993, the Faculty of Arts and Science and the Department of Astronomy and Astrophysics at the University of Toronto established the Helen Sawyer Hogg Distinguished Visitorship as a memorial tribute
Induction into the Canadian Science and Engineering Hall of Fame in May 2004, in Ottawa
Induction into the circle of Lowell High School Distinguished Alumni in November 2010
Helen Sawyer Hogg has been honoured by the department and the university on its Great Past website, Great Minds of the Past



Professor Hogg was a prolific writer, publishing many scholarly articles but also many for the public. The links below contain a selection of her writings.

Professor Hogg - Reflections on Her Life in Astronomy

Variable Stars in Globular Clusters: Helen Sawyer Hogg’s Presidential Address to the Canadian Astronomical Society
(1973, JRASC 67, 8)
Helen Sawyer Hogg was the founding president of the Canadian Astronomical Society when it formed in 1971. In her presidential address to the Society on May 12, 1972, she gave some personal reminiscences of her astronomical career which began in 1926.


SHAPLEY’S ERA: Helen Sawyer Hogg’s Memories of Harlow Shapley
(1988, IAU Symposium 126, 11)
To mark the centennial of Harlow Shapley’s birth, Harvard College Observatory hosted an IAU Symposium in August 1986: The Harlow Shapley Symposium on Globular Cluster Systems in Galaxies. Professor Hogg knew Shapley well. He had been her thesis supervisor when she was at Harvard (1926-1930) and after she left, they maintained a regular correspondence for the rest of his life. She was invited to speak about Shapley at the symposium and her talk was published in the conference proceedings.


Memories of the Plaskett Era of the Domionion Astrophysical Observatory 1931-1934.
(1988, JRASC 82, 328)
In 1988, the Canadian Astronomical Society and the Royal Astronomical Society of Canada established an award to honour John Stanley Plaskett, the director of the Dominion Astrophysical Observatory from 1918 when it opened, until 1935. It was at the DAO that Professor Hogg began her own observing program to discover and classify variable stars in globular clusters, after her graduation from Radcliffe in 1931. In a special issue of the  RASC Journal in 1988, she wrote an article about her memories of Plaskett and the DAO.


The Astronomy Column in the Toronto Star
(1981, David Dunlap Doings, January issue)


Forty Years with an Astronomy Column – Behind the Scenes View
(1981, Cassiopeia, Vernal Equinox Issue)
For thirty years, beginning in January 1951, Professor Hogg wrote a weekly column on astronomy for the Toronto Star, a major Toronto newspaper. (Her husband Frank had wrtten the column for the previous ten years.) After her final column appeared, on January 10, 1981, she recorded her memories in the DDO Doings, the David Dunlap Observatory newsletter, and in Cassiopeia, the newsletter of the Canadian Astronomical Society.


University of Toronto Archives: Accessions Database
Professor Hogg’s personal papers have been donated to the Archives of the University of Toronto.

Professor Hogg - Publications
Catalogues of Variable Stars in Galactic Globular Clusters

In 1939, Helen Sawyer Hogg published a catalogue of variable stars in globular clusters to enable researchers interested in the subject to get a clear picture of exactly what work had been done. Updates to the catalogue were produced in 1955 and 1973. All three editions were published in the Publications of the David Dunlap Observatory, University of Toronto. Subsequent to Professor Hogg’s death in 1993, this catalogue has been kept up to date by Professor Christine Clement at the University of Toronto.


First edition: 1939, DDO Publications, Volume 1, Number 4 (Helen B. Sawyer)
The first edition is available from Smithsonian/NASA ADS Astronomy Abstract Service.


Second Edition: 1955, DDO Publications, Volume 2, Number 2 (Helen B Sawyer)
The second edition is available from Internet Archive Canada – University of Toronto.


Third Edition: 1973, DDO Publications, Volume 3, Number 6 (Helen Sawyer Hogg)
The third edition is available from Internet Archive Canada – University of Toronto.


In preparation for a fourth edition, Professor Hogg kept a card catalogue based on relevant articles published in the literature up to 1988. She died in 1993. These cards have been deposited with the University of Toronto Archives and Records Management Services (UTARMS), along with her other personal records.


The catalogue has been kept in electronic format since 1997, including the material from Professor Hogg’s card catalogue. In 2001, the catalogue was further updated using references listed in the Astronomy and Astrophysics Abstracts (published for Astronomisches Rechen-Institut by Springer-Verlag) and the NASA Astrophysics Data System. A summary was published in a 2001 paper by C. Clement, A. Muzzin, Q. Dufton, T. Ponnampalam, J. Wang, J. Burford, A. Richardson, T. Rosebery, J. Rowe and H. Sawyer Hogg (2001, Astronomical Journal, Volume 122, pages 2587-2599).


The catalogue, which is continually updated by Professor Clement, can be found at this link.



Photos of Professor Hogg

Wearing the Order of Canada


With the DDO dome in the background


One of the last photos of her




In June 1992, the 61 cm Telescope of the University of Toronto Southern Observatory was dedicated in honour of Professor Helen Sawyer Hogg. A ceremony was held at the David Dunlap Observatory and University of Toronto President J. R. S. Prichard performed the dedication.

Programme of the The Helen Sawyer Hogg Telescope Dedication

Dedication of the 61 cm Telescope of the University of Toronto Southern Observatory in Honour of Professor Emeritus Helen Sawyer Hogg

JUNE 19, 1992




Welcome and Opening Remarks     E.R.Seaquist  
				David Dunlap Observatory

The University of Toronto	R.F. Garrison
 Southern Observatory 		Associate Director
 61 cm Telescope		University of Toronto
				  Southern Observatory

Helen Sawyer Hogg's Career 	C.T. Bolton 
				Associate Director
				David Dunlap Observatory

Helen Sawyer Hogg as a		M.A. Chandler
 Role Model			Dean
 				Faculty of Arts and Science

Dedication of the UTSO 		J.R.S. Prichard 
 Telescope in honour of    	President
 Helen Sawyer Hogg		University of Toronto

Closing Remarks 		E.R.Seaquist

Remarks prepared by Donald MacRae and read by Tom Bolton
On the Occasion of the Dedication of the 61 cm Telescope of the University of Toronto Southern Observatory in Honour of Professor Emeritus Helen Sawyer Hogg

I sincerely regret that a long-standing engagement is preventing me and my wife from being present at this dedication ceremony. We are disappointed not only because of our regard and affection for Helen Hogg, but also because the telescope in Chile is such an important part of astronomy at the University of Toronto.

When I first became associated with the David Dunlap Observatory, as a summer student assistant in 1936 and as an observer cum plate-measurer in 1937-38, Helen Hogg was, if she will pardon the word, a fixture. She had already established herself in her unique scientific niche — variable stars in globular clusters. Several times a year the 74-inch mirror would be resilvered (not until a year or two later could it be aluminized) and the telescope would be converted from Cassegrain to Newtonian form, so that Helen could use it for a week or ten days for a timely expansion of her collection of photographs of the stars in her favourite clusters.

Cassegrain observing, let it be said, was and is relatively safe and sensible; the observer is always on the floor of the dome or a few feet up at the eyepiece. But observing at the Newtonian focus was a different matter. For all the long night Helen would work alone, perched in the cantilevered cage at the top end of Canada’s largest telescope, high above the floor and with everything below in total darkness.

Her husband Frank, and later Gerry Longworth or Frank Hawker, would be down there below, moving the telescope when need be and changing the photographic plates in the plate holders as the photographs were taken and the night wore on. Inexperienced Newtonian observers like myself were not particularly welcome on those nights.

I remember going up to the empty Newtonian cage on one of my regular nights, however, just for a look at the sky, and finding a very peculiar object on the floor of the cage. It was a rather substantial woman’s handbag, with a firm clasp, and attached to it was a very long rope. I was mystified until Gerry Longworth explained. That was how Helen sent the exposed plate down to husband Frank, and how she hauled up the fresh unexposed plate for the next shot. I wonder if Helen still has that dedicated bag. I wonder if the modern New Technology Telescopes deal as efficiently with problems of this sort.

The night’s work would go on in silence and darkness, except for the mesmerizing sound of the drive motor and the occasional clicks from Helen’s guiding. I am told, though, that sometimes a piercing reverberation would shatter the silence of the dome. It would be Helen’s voice as she commented with great excitement on something or other than she had seen from her vantage point, perhaps a threatening cloud on the far horizon, or a meteor near her field of view. Whatever it was that she said was always quite unintelligible to those on the floor, the words and meaning being lost in the echoes and re-echos of the hollow dome.

There came a time when Helen had another of her novel ideas. “Most of my globulars are in the constellations of the southern sky. Why not apply for time on a telescope at a southern observatory where they would be more accessible?” Nowadays we all take this sort of thing for granted. But fifty or sixty years ago few if any astronomers went away off from home just to observe for a short period. Helen became one of the first “suitcase astronomers” when she applied to Edwin F. Carpenter, the Director of the Steward Observatory of the University of Arizona, and was granted observing time on the 36-inch (91 cm) diameter telescope near Tucson. That was about as far south as she could go then, and it was quite a journey — much more of an undertaking than is required nowadays to make a trip to the U. of T. Southern Observatory in Chile. I think it is accurate to say that Helen Hogg was the first Canadian astronomer who went south specifically for the sake of the richness of the southern sky, and the darkness and fine seeing of a dry desert site. It was the auspicious initiation of a habit that is now quite routine for many University of Toronto students and staff.

It was no wonder that DDO sought a southern site for a telescope of our own in the late sixties. Helen’s record of research gave us one of our major incentives to establish a foothold on Las Campanas in Chile. Regrettably, Helen herself has not yet been there. But, in the field of variable stars in clusters which has been for so long Helen Hogg’s specialty, several associates, notably Dr Christine Clement, have stepped in and are helping to fulfill the telescope’s purpose.

Moreover, under Bob Garrison’s guidance, and hard work by the DDO support staff, the telescope has been kept in step with modern instrumentation. Perhaps the biggest change is that photographic plates, on which Helen so long depended, are being phased out. Instead, the latest electronic devices, more efficient and more trustworthy, are routinely in use.

In the past we at DDO have been very proud of our southern telescope. For the future, we see it as being an instrument that is remarkably versatile, and continuously productive of first class research. It will fully deserve the new name it is about to receive.

Tom Bolton's Remarks
On the Occasion of the Dedication of the 61 cm Telescope of the University of Toronto Southern Observatory in Honour of Professor Emeritus Helen Sawyer Hogg

(After reading MacRae’s prepared remarks)

“Gee, I wish I had said that!” That is a tough act to follow.

You received a brief summary of Helen’s career highlights along with today’s programme when you arrived. I made up this summary at the last minute, so I hope I have gotten everything right. Our files are sometimes contradictory. If there are any mistakes, they will be corrected in the version published in the booklet.

Relatively little has been said about Helen’s research in the earlier speeches, and I suspect the ones that follow will also have little to say about this aspect of her career. I would like to fill that gap because I think it is fair to say that if she had not been a distinguished researcher we would not be here today.

Helen was a student of Harlow Shapley, a giant of 20th century astronomy and perhaps one of the most important men in the history of astronomy. The research that grew out of her work with Shapley is a long term programme to discover and study variable stars in globular clusters. Helen took thousands of plates of these clusters over a period of approximately 40 years using the 72″ telescope of the Dominion Astrophysical Observatory in Victoria and the 74″ telescope at the David Dunlap Observatory. She and her collaborators took thousands and thousands of other plates with smaller telescopes here and in Chile.

Helen is quoted in the cover story of the September/October 1985 issue of the University of Toronto Graduate as follows: “I don’t think I have made that many earthshaking discoveries, it’s just a case of working along and accumulating a lot of information in one area”. Her modesty is commendable, and perhaps there’s an element of truth in it, but I don’t think that it’s a fair description of her contributions. If it was really as easy as she suggests, everybody would be doing it! Clearly, everybody can’t do it! Moreover, Helen showed great courage and faith in the future by starting a long-term programme when she didn’t have a job- at least not a paid position. I know of very few contemporaries of mine, and even fewer recent Ph.D.’s, who’ve had the guts to do that, even when they had a job.

Helen’s intellectual contributions were her foresight and judgement in picking an exceptionally interesting group of objects for study, her organization of a well defined and interesting observing programme, and her careful, systematic analysis of the data over a long period. It’s not easy to do all of these things. Lots of people have tried, even some of her contemporaries at this Observatory, but few have been as successful as Helen.

Helen’s work has not always been fully appreciated. Her discovery, early in the observing programme, of a nova, an exploding star, in a globular cluster, is perhaps the best example of this. As far as I know, this is still a unique observation. There was renewed interest in this observation a couple of years ago when the Hubble Space Telescope resolved the faint stars in the center of the globular cluster for the first time. The scientists involved with the Hubble Space Telescope observations borrowed the discovery plate from Helen to measure to see which of these stars was the remnant of the nova explosion. That was great. Helen was thrilled with this renewed interest in her discovery. Unfortunately the HST boys ruined the experience for Helen by describing her discovery as serendipitous, accidental in other words(!), in the news release about their work. No, no, no! It wasn’t an accident. Her research program was designed to systematically look for variable stars in globular clusters. Helen’s discovery of the nova was the result of careful planning, not an accident.

Helen’s research on variable stars in globular clusters is not her only contribution to astronomy. As Don noted in his remarks, she was perhaps the first Canadian to go South for the right reasons- observing not holidays. She was also, I think, one of the first astronomers of any nationality, to realize the value of careful bibliographic work. She exploited the assets of our very fine library to prepare bibliographies and catalogues in her specialty. The power of the computer has made the compilation and analysis of astronomical bibliographies and databases important new fields of astronomical research. Helen anticipated the importance of this work, but she had to do it the hard way!

When I first joined the Observatory staff, there was a drawer that was sometimes described as “Helen’s drawer” in a library table. I wasn’t told about this drawer when I arrived, but after a few months, I noticed that new journals and preprints seemed to disappear from the library for some time before reappearing. Try as I might I couldn’t find them. Eventually someone told me that the missing material could be found in Helen’s drawer, where they were kept until Helen had a chance to go through them. Those who knew about the drawer were allowed to use the materials in it as long as they remembered to put them back where they were found. Otherwise, they were assured of great woe.

Helen has been an inspiration to many, many students at the University of Toronto. She has a contagious, almost childlike excitement about both her research and the beauty of the objects which she observes that has left a lasting impression on everyone that knows her. I have no doubt that she helped stimulate the creation of the variable star group here at the University of Toronto. She was also an inspiration for several of the astronomers that began the strong Canadian globular cluster research group. This group started at the University of Toronto in the 1960’s, and it now has members in all of the important Departments of Astronomy and optical observatories in Canada.

Finally, I would like to say a few words about Helen’s contributions to various professional and other organizations. She has given her time very generously to many organizations, especially the Royal Astronomical Society of Canada, the Canadian Astronomical Society, the Royal Society of Canada, and the Royal Canadian Institute, and she continues to have an active interest in these organizations. Her skills in handling people, her judgement and business sense have enabled her to make many valuable contributions to these organizations.

I think I saw the best example of the respect that her colleagues hold for Helen in 1971. In November of that year astronomers from all across the country gathered in Toronto to discuss the future of our community in the aftermath of the failure of the Queen Elizabeth II Telescope project. The QE II telescope was supposed to have been a 4 m telescope located in southern British Columbia. The Federal Government had denied funding for the project a couple of years earlier when the astronomical community had split along both geographical and university-government lines over whether the planned location was suitable for a large telescope. As a result, there were lots of hard feelings between proponents and opponents of the project.

I had been in Canada only slightly over a year at the time of the meeting. I was meeting most of the Canadian astronomers for the first time, but I didn’t have to know the protagonists to see that the atmosphere at the meeting was tense. Nearly all of the major figures in Canadian astronomy had polarized into two factions. Whenever I walked into the meeting room, it felt as though the temperature dropped about 20 degrees. During the discussions, each word seemed to be covered with frost, and visual daggers were flying thick and fast about the room. As a recent immigrant from the United States, where we’re more schooled in the “gunfight at the OK Corral” than the “compromise at Meech Lake” style of dispute settlement, it seemed to me that there was no way that the deep rift between the groups could be patched up.

Fortunately, everyone understood that we had lost an opportunity to move to the forefront of astronomy and that we we were never going to have another opportunity unless we found a way to work togther. Somehow everyone managed to put aside their hard feelings so that we could agree on a plan. The Canadian Astronomical Society (or CASCA as it became known from its combined English and French initials) was formed to act as a unifying force for professional astronomers and speak to the government on behalf of the professional astronomers.

Since I did not yet know Helen well, I was surprised when she was chosen as the first president of CASCA. In retrospect, I can see that she was chosen because of her skill in handling people, the respect that her colleagues had for her and the fact that she was seen as above, or capable of putting herself above, the dispute that had divided the community. The choice was inspired. By the end of her term, CASCA was recognized inside and outside the astronomical community as the authentic voice of the community. CASCA created a favourable climate for consideration of the proposal from France that Canada join them in building a 3.6 m telescope in Hawaii, the Canada-France-Hawaii Telescope.

Unfortunately, I’ve taken so much time to tell you about my colleague Helen that I don’t have any time left to tell you about my friend Helen. I’ll just close by saying that Helen has been an inspiration to my wife, Susan, and me in many ways, and her friendship has enriched our lives enormously. I know that is also true for my colleagues at the Observatory.

Thank you very much.

Response by Helen Sawyer Hogg
On the Occasion of the Dedication of the 61 cm Telescope of the University of Toronto Southern Observatory in Honour of Professor Emeritus Helen Sawyer Hogg

President Prichard and distinguished guests, staff and friends. I find it hard to get words to thank you for this magnificent plaque which I think was made in our own, very superb workshop with the wonderful skill of our own staff right here. I want to thank too, the speakers who have preceded you, President Prichard, Bob and Tom and Ernie and Dean Marsha for that gorgeous bouquet, that I can see a little later, and I thank you for your most generous remarks about me – kind of overwhelming to tell the truth.

Well, now I realize that in my remarks, I am in a unique position of having worked here at the David Dunlap Observatory for at least 57 years, and I say at least, because although the time has come when I thought I should give up my most convenient office, I’ve still got the keys to the Observatory! I can come and work in that most beautiful library anytime I want.

So, in this unique position, I wanted to use my few moments to pay tribute to the two people whom I knew that were the founders of this Observatory – Jessie Donalda Dunlap and Dr. C.A. Chant, carrying out the wishes of David Dunlap. And from the time the Observatory was founded when the son of Jessie Donalda and David Dunlap, Moffat Dunlap (whose sons are here today) laid the cornerstone, the spirit of this Observatory has been one of terrific devotion to the cause of astronomy. I have seen the staff and the students carry that out for six decades and it has been a wonderful experience. It has given me pleasure, personally, to see my own field of variable stars and globular clusters carried on by my former student Dr. Christine Clement. And my associate Dr. Amelia Welhau of the University of Western Ontario was the one who was working on my 1938 plates of the globular cluster Messier 14 and spotted the image of that very important nova.

Now, we hear a great deal in the media these days about World War II. The war years at the David Dunlap Observatory were very hard. Not many people here can remember those years at the Observatory – Dr. John Heard and Dr. Peter Millman enlisted in the Royal Canadian Air Force; Gerry Longworth enlisted in the Royal Canadian Navy; George Tidy, an assistant, ended up as a prisoner in a Japanese Prisoner of War Camp. Left behind were Dr. R.K. Young, Dr. Frank Hogg, with a heart ailment, and Ruth Northcott who ran the 74″ telescope nights and taught classes at the St. George Campus of the University of Toronto by day. Hard years.

In the 1950s the staff, and the graduate students expanded greatly in number and in later decades sophisticated secondary instruments were developed to help counteract the increased brightening of the sky around Richmond Hill. It happens that, just now, one of Dr. Don Fernie’s early electronic instruments is being mounted for display in the National Museum of Science and Technology in Ottawa.

It makes me very humble, President Prichard, to think that I have been chosen to represent, in a manner of speaking, this wonderful spirit of the David Dunlap Observatory at its Southern Hemisphere Observatory, I think of David Dunlap and Jessie Donalda Dunlap and Clarence Augustus Chant and dedicated members of staff and students in these six decades since the cornerstone was laid and I am very humble.

President Prichard, we do not think that you have time to take the excellent courses that the Department is running, but perhaps this popular book of astronomy…(Dr. Hogg’s book “The Stars Belong to Everyone”)… might answer some of your questions!

About the UofT Southern Observatory, Chile

National Museum of Science and Technology, Canada. The Helen Sawyer Hogg Observatory Le télescope du Musée et l’observatoire Helen Sawyer Hogg



In 1985, on the occasion of Helen Sawyer Hogg’s 80th birthday, the University of Toronto Graduate magazine published an article by Judith Knelman.

Article from the Graduate


by Judith Knelman

Reproduced with permission from the Graduate: the University of Toronto Alumni Magazine (photographs omitted)
Volume XIII No.1, September/October 1985

Astronomer Helen Sawyer Hogg remembers being allowed to go out after dark one spring evening in 1910 to see Halley’s Comet. “I don’t remember much about the experience,” she says, “but I can still visualize the thing with its lovely tail.” She was five then, growing up in Lowell, Mass., in a family drawn to nature. Her father, a banker, and her mother and aunt, former schoolteachers, encouraged her to observe and learn about wildflowers and ferns and leaves and rocks and stars. Which she did, receiving a Ph.D. in astronomy from Radcliffe in 1931 for her work at the Harvard College Observatory, so that when she sees Halley’s Comet again in 1986 she’ll be able to absorb a little more from the experience. She says in an article in the Queen’s Quarterly (written with her son David, also an astronomer): “Its period of around 76 years has permitted a large proportion of the earth’s in habitants to see it once. A favoured few see it twice.”

Though Hogg, who taught at U of T for 31 years and has been doing research at the David Dunlap Observatory since 1936, turned 80 last month, she shows no signs of wanting to retire to a rocking chair on the front porch to watch the world go by. Her job is to watch the universe go by. “I’ve spent 59 years working in this field, and I’m not through yet,” she says.

An internationally recognized authority on variable stars in globular star clusters, she observes changes in the size, temperature and brightness of hundreds of stars in globular star clusters in order to be able to estimate, among other things, their age and their distance from the sun. That adds to the information we have on our galaxy, the Milky Way, which contains about a hundred thousand million stars, one of which is our sun, and is just one of millions of galaxies in the universe.

About 130 globular clusters outline the Milky Way. (Galaxies more massive than our own have more clusters – perhaps as many as 10,000.) Each cluster contains tens of thousands to hundreds of thousands of stars moving in slow and beautiful symmetry around a common centre of gravity as the cluster itself orbits around the centre of the galaxy. The orbits take millions of years to complete. Clusters were the first stellar formations: with ages of 16 to 18 billion years, they are close to the age of the universe.

So information about the way in which their stars – globes of glowing gas – pulsate as their nuclear-generated energy pours out is extremely useful. It takes years to accumulate, though. A star’s cycle from bright to faint to bright again takes anywhere from days to hundreds of days. Clusters are only observable during our summer months, and if someone else needs the telescope, or clouds come up, or the sun gets between the earth and the cluster, the observer may have to wait a year for another chance to document the cycle further.

Hogg has not only taken about 2,000 photographs of clusters at various points in their stars’ life cycles but has also published her findings in numerous scientific papers. As the authority on the subject, she has combined them in a series of catalogues – the only such compilations that have ever been published – with the discoveries of other astronomers working in the same field of research. Her first catalogue was published in 1939, and she is now working on her fourth up-to-date version.

That is the way scholarship works in astronomy. When you deal in billions of years and in distances of tens of thousands of light years, 59 years of observing does not seem a great deal. “I don’t think I’ve made that many earth-shaking discoveries,” says Hogg self-deprecatingly. “It’s just a case of working along and accumulating a lot of information in one area.”

She is still doing bibliographical work and working with the glass negatives produced by other observer- photographers, but several years ago she gave up personal observing. Staying up all night and moving the huge telescope around was just too strenuous. “I find I don’t have the physical strength I used to. I read of go-getters like Bob Hope, who’s 82, and marvel at them. I haven’t that kind of energy. But I’m still working every day.”

Helen Hogg’s first job was as a teacher at Mount Holyoke College, where she had done her undergraduate studies. In 1931 she gave that up to accompany her Ontario-born husband, Frank, also an astronomer, to Victoria, where he had a job as a researcher with the Dominion Astrophysical Observatory. Rumour had it that Cecilia Payne, now regarded as the foremost woman astronomer of all time, had been turned down for the job because it would not be proper for a woman to spend nights in the dome with male technicians.

There was no question in the depression years of a wife’s being employed at a government service where her husband worked, but Helen didn’t mind being unemployed as long as she had access to the telescope at Victoria, which was the second-largest in the world at the time. As long as her husband was willing to chaperone her, she was allowed to do her observing. So by virtue of being a married woman, she was able to use the telescope to which brilliant Cecilia Payne had been denied access. Far from being held back in her career by her marriage, she was actually advancing beyond the boundaries established for unmarried female astronomers.

The first year, Helen spent many a winter night keeping Frank company as he worked on his programs of observation. That summer she had a baby and took her up in the dome in her basket on several occasions so that she could be fed on time. Helen was not held back by motherhood. She was going places, even though she wasn’t being paid. Indeed, she was establishing a scientific reputation every bit as impressive as her husband’s.

In 1935 Frank took a position as a lecturer and researcher at the new David Dunlap Observatory of the University of Toronto, whose telescope bumped the one in Victoria to third place. The second year the Hoggs were in Toronto, J.S. Plaskett, director of the Dominion Astrophysical Observatory in Victoria, managed to get Helen a research grant from the National Academy of Sciences for $200, which bought her the services of a maid for a year. “If I had it to do over again in present times of household help I don’t know how I’d manage,” she says. “I’m not sure I could take children to day-care centres. I was brought up that home is where the child is unless it is in school.”

From 1936 on she was working virtually full-time. In 1941 her responsibilities increased as male astronomers went to war, and she became a lecturer as well as a researcher. Most of her teaching was directed at the general student who wanted to know something about astronomy but wasn’t anxious to take more than one course in it.

Frank Hogg died on Jan. 1, 1951, five years to the day after he became director of the observatory. “It was a difficult time then. He was taken very suddenly, and then when somebody who’s director and head of the department goes it leaves a void.

“I myself was teaching and I had the children, so it was a heavy time.” Helen went on with her research and took on a column on astronomy for the layman that her husband had been writing for the Toronto Star, which ran for 30 years and grew into a book on popular astronomy, The Stars Belong to Everyone: How to Enjoy Astronomy (Doubleday, 1976).

Meanwhile, she was rising through the ranks at the University, becoming a full professor in 1957. In 1950 she received the Annie J. Cannon prize of the American Astronomical Society, an international award given once in three years to a woman astronomer for her research. In 1958 she received an honorary doctorate from Mount Holyoke. In 1959 she was elected president of the Royal Astronomical Society of Canada. In 1962 the University of Waterloo awarded her an honorary degree. In 1964 she became the first female president of the Royal Canadian Institute. In 1967 she received four medals: the Rittenhouse Medal of the Rittenhouse Astronomical Society of Philadelphia, the Service Award Medal of the Royal Astronomical Society of Canada, the Radcliffe Graduate Achievement Medal and the Centennial Medal of Canada. The following year she was appointed an Officer of the Order of Canada. In 1971 she became the first president of the Canadian Astronomical Society. In 1972 an International Astronomical Union colloquium was held at the University of Toronto in honour of her life work. In 1976 she was promoted to Companion of the Order of Canada.

That year she retired from teaching and was named Professor Emeritus. The following year she was awarded an honorary degree by U of T. In 1981, the year she stopped writing her newspaper column, she collected an honorary degree from St. Mary’s University. She continued going into the Dunlap Observatory every day, methodically adding to astronomers’ knowledge of variable stars in globular clusters. Her career seemed to be drawing quietly to a close.

Then in the spring of 1983, with the receipt of the Dorothea Klumpke-Roberts award, given by the Astronomical Society of the Pacific for her fostering of public understanding and appreciation of astronomy, the honours started coming in again. The following year the International Astronomical Union named a minor planet Sawyer Hogg after her in recognition of her scholarly and popular contributions to astronomy. (A lunar crater had already been named Hogg after her husband.) In July 1984, she officially opened the Edmonton Space Sciences Centre and was named honorary chairman of the board of directors of the Faculty of Science Foundation at the University of Waterloo. In January of this year a special session was held in honour of “Canada’s most distinguished and beloved astronomer” at a joint meeting in Toronto of the American Association of Physics Teachers and the American Physical Society. In March she received an award of merit from the Toronto City Council for the distinction she has attained in her field. In April she was presented with the Royal Canadian Institute’s Sandford Fleming Medal. In May she flew to Alberta to receive an honorary doctorate from the University of Lethbridge and open the university’s Astrophysical Observatory and immediately returned to Toronto to attend the first Helen Sawyer Hogg annual public lecture of the Canadian Astronomical Society.

“It’s one of those strange things that all these things are happening now,” said the seasoned observer of strange things. But a colleague, Donald MacRae, director of the observatory and chairman of the department from 1966 to 1978, offered a more logical explanation: “She’s sort of a first lady of science. When people think of women who have succeeded in their scientific careers, they naturally think of Helen Hogg.”



Articles published after Helen Sawyer Hogg’s death in 1993

Obituary from the RASC Journal
by Christine Clement and Peter Broughton

Reprinted with permission of the Royal Astronomical Society of Canada.
From the RASC Journal, V.87, No.6 December 1993

Canada lost one of its most famous and best-loved astronomers with the death of Professor Helen B. Sawyer Hogg in Richmond Hill, Ontario on January 28, 1993.

Dr. Hogg was an active member of the RASC for more than 60 years. She addressed meetings of nearly every Centre at one time or another from her first talk to the Victoria Centre in 1933 on the subject of the Magellanic Clouds to her invited lecture on variable stars at the Halifax General Assembly in 1980. Toronto was especially fortunate to be able to call her to speak on many occasions ona wide range of topics. Dr. Hogg was always interested in the functioning of the Society and served on the Toronto Centre Council during the 1940s and 50s prior to becoming national President in 1957. Durung her Presidency, she was influential in getting Council to meet for the first time outside Toronto and in the extension of the Annual Meeting to a two-day format allowing for members to present papers. She prepared a promotional pamphlet on the aims and operations of the Society, and tried mightily to encourage those members who did not belong to a local Centre to feel a part of the Society. All these contributions, her keen interest, help and advice were recognized in the presentation to her of the RASC Service Award in 1967. These qualities were equally evident during her terms as Honorary President of the Toronto Centre (1972–77) and as Honorary President of the Society (1977–81). The Society’s deep respect for Dr. Hogg’s scientific work was marked in 1987 when she became the only Canadian among 15 eminent Honorary Members.

In 1985 the Helen Sawyer Hogg lectureship was established in her honour by the Canadian Astronomical Society and the RASC. Each year since, this public lecture has been delivered at the annual meeting of one of the two Societies. The most recent was given at the University of Victoria in June, 1993, and attracted an audience of 1000.

Helen Battles Sawyer was born in Lowell, Massachusetts on August 1, 1905 and received her early education in Lowell public schools. Her university career began in 1922 with undergraduate studies at Mount Holyoke College. At the beginning of her time there she planned to become a chemist. However, an event in the winter of 1925 made her change her mind. There was a total eclipse of the sun on January 24, 1925 and her astronomy professor, Anne Young, arranged for a special train to take the students to a site in Connecticut to view the eclipse from inside the path of totality. Years later, Helen said that “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”. A year later, in January 1926, Annie J. Cannon of the Harvard College Observatory visited Mount Holyoke for a few days and Helen had an opportunity to meet with her several times. After their meeting it was arranged that Helen would go to Harvard to work with the renowned Dr. Shapley for graduate studies. She received an A.B. (Magna cum Laude) from Mount Holyoke in the spring of 1926 and started her work at the Harvard Observatory a few months later. Helen was the first student that Shapley supervised for a doctorate on the subject of star clusters, the field in which he had made his name. She worked closely with Shapley during her years at Harvard and had her name on a dozen papers before she submitted her doctoral thesis. She received an A.M. in 1928 and Ph.D. in 1931, both from Radcliffe College, because at that time Harvard did not give graduate degrees in science to women.

In 1930 she married fellow student, Frank Hogg, and after her graduation in 1931 they moved to Victoria, British Columbia, where Frank was appointed to the staff of the Dominion Astrophysical Observatory. In Victoria, initially as an unpaid volunteer, Helen started her own observing program with the 72-inch ($1.8$ m) telescope to search for and study variable stars in globular clusters. In those days it was not considered proper for a woman to spend nights in the dome alone with male technicians, but since her husband was willing to chaperone her, she was able to do her observing. While the Hoggs were in Victoria their first child, Sally, was born. When barely a month old even baby Sally participated in the family “globular cluster enterprise” by accompanying her parents to the dome at night in her basket.

In 1935 the family moved to Ontario, where Frank joined the staff of the University of Toronto. Helen continued her observing program with the 74-inch telescope at the university’s David Dunlap Observatory, and received her first appointment from the University of Toronto in 1936 as a Research Assistant. The Hoggs’ other two children, David and James, were born in 1936 and 1937 after the move to Ontario. Having three young children did not slow Helen down in her professional activities. She continued with her observing and publishing and in 1938 attended the IAU General Assembly in Stockholm when the 250 delegates at the meeting were invited to the Royal Palace by the King of Sweden. In 1939 she travelled to the Steward Observatory in Arizona to photograph globular clusters that were too far south to be observed from the Dunlap Observatory in Richmond Hill and secured 300 plates in six weeks. She also went that same year to Texas for the opening of the McDonald Observatory. In 1940–41 she was the acting chairman of the astronomy department at Mount Holyoke. Her teaching duties at the University of Toronto started in 1941 during the second world war. Later reminiscing about those days, Helen said, “The war years at the David Dunlap Observatory were very hard. Dr. John Heard and Dr. Peter Millman enlisted in the Royal Canadian Air Force; Gerry Longworth enlisted in the Royal Canadian Navy; George Tidy, an assistant, ended up as a prisoner in a Japanese Prisoner of War Camp. Left behind were Dr. R.K. Young, Dr. Frank Hogg, with a heart ailment, [Helen] and Ruth Northcott, who ran the 74-inch telescope nights and taught classes at the St. George campus of the University of Toronto by day. Hard years.” In 1946 after the war, Frank Hogg became the Director of the Observatory, a post he held until his sudden death in 1951. In spite of this tragic loss, Helen kept on with her work and rose through the academic ranks at the University of Toronto to become a Full Professor in 1957. In 1976, she was appointed Professor Emeritus. In 1985, Helen married F.E.L. Priestley, Professor Emeritus of English at the University of Toronto. Professor Priestley died in 1988. However, during the brief time that he was married to Helen he also made a contribution to Canadian astronomy. He had two articles published in the Society’s Journal in 1986 and 1987: Halley Greets Newton’s Principia and Newton and the Apple.

In the international astronomical community, Helen was very well known for her research on variable stars in globular clusters. She took over 2000 photographs, discovered hundreds of variables and published more than 200 papers. Her knowledge of the night sky was phenomenal. Even on cloudy nights when she was scheduled to observe at the David Dunlap Observatory, she always watched for breaks in the clouds just in case one of “her clusters” might appear. She never missed an opportunity. Her Catalogues of Variable Stars in Globular Clusters are valuable reference sources that are frequently cited in the literature. She published three editions: in 1939, 1955, and 1973, and was working on the fourth at the time of her death. An IAU Colloquium was held in honour of her life work in this field at the University of Toronto in 1972.

Over the years, she also wrote a number of articles on historical astronomy in the Journal, many of them in her feature Out of Old Books. However, to most Canadians, she was probably best known for her work in public education. For thirty years (1951 to 1981), she wrote a weekly column entitled With the Stars for the Toronto Star. In 1970, she presented her own astronomy series on TV Ontario, and in 1976 her popular book on astronomy, The Stars Belong to Everyone, was published by Doubleday Canada.

Professor Hogg was active in several professional organizations in addition to the RASC. On a leave of absence from Toronto in 1955–1956, she became Program Director for Astronomy, National Science Foundation, Washington, D.C. She was President of the American Association of Variable Star Observers (1939–1941), International Astronomical Union Subcommission: Variable Stars in Star Clusters (1955–1961), Physical Science Section of the Royal Society of Canada (1960–1961), Royal Canadian Institute (1964), and councillor of the American Astronomical Society (1965–1968). In 1968, she was one of the first two women appointed as directors of the Bell Telephone Company of Canada and was re-elected as a director at every annual meeting until her retirement from the Board in 1978. She was the founding President of the Canadian Astronomical Society when it formed in 1971.

Throughout her distinguished career she received numerous awards and honours. In 1949, she won the Annie J. Cannon prize of the American Astronomical Society. In 1967, she was the first Canadian to be awarded the Rittenhouse Medal of the Rittenhouse Astronomical Society, Philadelphia; the same year ske received the Radcliffe Graduate Achievement Medal and the Centennial Medal of Canada. In 1968, she was awarded the Medal of Service of the Order of Canada and in 1976 was promoted to Companion of the Order. In 1983, she received the Dorothea Klumpke-Roberts award from the Astronomical Society of the Pacific for her work in public education. She received the Order of Merit, City of Toronto in 1985 and the Sandford Fleming Medal of the Royal Canadian Institute that same year. In 1992, a few months before her death, the Commemorative Medal for the 125th Anniversary of the Confederation of Canada was conferred upon her. In addition, there were honorary degrees from Mount Holyoke in 1958, University of Waterloo in 1962, McMaster University in 1976, University of Toronto in 1977, Saint Mary’s University in 1981, and the University of Lethbridge in 1985. She held honorary life memberships in the Ontario Field Naturalists, the Royal Canadian Institute, the University Women’s Club of Toronto, and Science North, Sudbury. Two facilities were dedicated to her: the observatory at the National Museum of Science and Technology in Ottawa, and the telescope at the University of Toronto’s southern site in Chile. Asteroid 2917 was named Sawyer Hogg in her honour in 1984.

Professor Hogg was an important role model for women in the Physical Sciences. Throughout her life she encouraged women to pursue careers in science. In fact, only a few days before her death she participated in the taping of a video sponsored by the University of Toronto to attract young women into the sciences.

Although Helen Hogg’s professional accomplishments are numerous, one can not write an account of her life without mentioning what a gracious and thoughtful person she was. For decades she entertained RASC members, Department of Astronomy staff, students and their families, either at her home in Richmond Hill or at the University Women’s Club at the campus of the University of Toronto. On many occasions she brought her freshly baked hermits to RASC meetings. She was also an expert knitter and made well constructed baby booties for generations of friends, relatives and associates. No baby could kick off those booties!

Throughout her life she was devoted to her family. She had three children, seven grandchildren, and four great grandchildren. Her son, David, is a radio astronomer at the National Radio Astronomy Observatory, Charlottesville, Virginia, and a Life Member of the RASC.

A funeral service was held at the Richmond Hill United Church on February 1, followed by interment at Lowell, Massachusetts, where Helen had been born 87 years earlier.

Christine Clement, Department of Astronomy, University of Toronto, Toronto, Ontario M5S 1A7

Peter Broughton, 31 Killdeer Crescent, Toronto, Ontario M4G 2W7


The source of the two quotations by Dr. Hogg are: Shapley’s Era by Helen Sawyer Hogg in The Harlow-Shapley Symposium on Globular Cluster Systems in Galaxies, ed. J.E. Grindlay and A.G. Davis Philip, pages 11–22, 1988 (solar eclipse of 1925) and Transcript of Dr. Hogg’s speech at the Ceremony of Dedication of the Helen Sawyer Hogg Telescope of the University of Toronto Southern Observatory on June 19, 1992 (the war years at DDO).

Obituary from Astronomical Society of the Pacific Publications
The scanned version of the obituary by Judith L. Pipher published in PASP is available from ADS
Article from UofT magazine, Edge (2000)
A brief article written by Althea Blackburn-Evans for the UofT magazine, Edge, in Winter 2000, with a photo of both Professors Hogg and Clement
Article in University of Toronto Magazine, 2015
She Walks in Beauty by Alec Scott in University of Toronto Magazine, Autumn 2015