Women who measured stars for the Great Star Catalogue: Margaret Colville and Winsome Bellamy
Dr Toner Stevenson, History Affiliate, School of Humanities, The University of Sydney
This blog post is to recognise Margaret Colville and Winsome Bellamy on International Women's Day 2024. They are two of the many women in Australia who made a contribution to astronomy through their important but are little known work on the Great Star Catalogue which is also called the Astrographic Catalogue.
In Australia 30% of the people working in astronomy are women (1). This is despite acknowledgement that a diverse workforce is important in all fields. It is clear that there is still some way to go in changing attitudes to working in the physical sciences and gender. It is only since 1966 that women had access to permanent employment in the Commonwealth public service after they married (2). It was legal to pay women less who were doing the same work as men until 1972 (3). Prior to 1972 there were few women professional astronomers although there were many women behind the scenes who were supporting the scientific work but often not recognised for their contributions. In some cases they were volunteer helpers, such as wives or daughters of astronomers, or paid as clerical assistants.
These women were ‘hidden figures’ in the history of astronomy in Australia. They worked behind the scenes on many projects and one of the most significant international astronomy projects of the 19th and early 20th centuries was the Astrographic Catalogue which began in 1887. The aim of this enterprise was to photograph and catalogue the positions and brightness of stars down to 11th magnitude for the entire celestial sphere. Australia ended up completing 18% of the sky and they had the most star-rich sections of the sky due to the proximity of the milky way (4).
The first women who measured stars on glass photographic negatives for the Astrographic Catalogue (AC) in Australia were employed from 1898 at Melbourne Observatory and in the early 1900s at Sydney and Perth Observatories (5). The repetitive measuring and computation was considered women’s work, only men were employed as astronomers.
Although the AC photographic work was completed by 1919, the measurement, computation and catalogue preparation was severely hampered by the lack of funds. The International Astronomical Union asked Harley Weston Wood (1911 - 1984) whilst he was acting NSW Government astronomer at Sydney Observatory to finish the Sydney and Melbourne zones. To assist he employed Margaret Colville (1926 - 1990) who worked at Sydney Observatory from 1941 to 1961, when she started she was 15 years old. Once he was confirmed as Director of Sydney Observatory, Wood accelerated work on the AC project, building a new observing dome, acquiring the Melbourne Astrographic telescope and employing more women.
Winsome Bellamy (1928 - ) was employed at Sydney Observatory from 1948 to 1968 on the AC. The women typically had the intermediate certificates and sat a public service exam which indicated their suitability. Colville taught Bellamy and then they worked as a team on measuring star positions and magnitudes for the Astrographic Catalogue. Bellamy and Colville were individually recognised by Wood (6) for their significant contributions to the Sydney and Melbourne zones. The Sydney zone consisted of 9,514 plates with 743,593 stars in the catalogue and the Melbourne zone had 4,507 plates with a total of 218,000 stars.
I first met and interviewed Bellamy in 2011 when I began my doctoral research and she described the work. Bellamy would sit at the measuring machine, looking through a small micrometer lens, which is similar to a microscope, at a photographic glass plate negative of the stars. The stars looked like tiny black dots and each star had to be centred in the micrometer’s centre line , which was made of spider web. Bellamy called out the location of the star on and she determined the brightness of the star, called the magnitude, by comparing this to the standard sizes which were on thin film and could be positioned in the eyepiece to compare.
Colville would carefully transcribe all of this into a log book. There could be hundreds of stars on each glass plate. After 30 minutes the women would swap places, and Colville would take her turn at the measuring machine. The star measurements were then checked by rotating the glass plate and re-measuring the positions of the stars. Once checked there was a logarithmic calculation for each star that the women did and then this figure was entered onto another logbook. Finally each plate was transcribed onto a manuscript for the printer to work from (7).
As you can see in the photograph taken by Bellamy during lunch time on Observatory Hill there was great camaraderie amongst the women who were working on the star catalogue. Bellamy never married but she attended many weddings of the others who then left the observatory due to social custom and employment law. Colville married in 1955 but she stayed on until 1961, she was most likely able to stay in her position due to Wood’s insistence that she was essential to the work. She was upgraded to Clerk Grade 1 in 1957. The final volume of the Melbourne zone was sent to the printer in 1961 and published in 1963; and the last of the fifty-two volumes of the Sydney zone of the AC was completed in 1964. Four years later Bellamy decided to leave and become a nurse, something she was passionate about prior to starting at Sydney Observatory,
Thankfully due to changes in the law and programs such as the SAGE (Science in Australia, Gender and Equity) accreditation (https://sciencegenderequity.org.au/) and The Pleiades Awards in astronomy (https://asa-idea.org/the-pleiades-awards/) there are now incentives for organisations to provide equal opportunities for women in astronomy and at the cutting edge of science in Australia.
Bio
Dr Toner Stevenson is an honorary History affiliate at The University of Sydney. She recently co-authored the book 'Eclipse Chasers’, published by CSIRO. She is active in amateur astronomy. Prior to working at the University of Sydney Toner had an extensive career in museums, including the Powerhouse Museum and as Manager of Sydney Observatory from 2003 to 2015. She is a Sydney City Skywatchers Committee member and on the Board of the International Council of Museums (ICOM) Australia.
References:
1. Kewley, L.J. 2021, Closing the gender gap in the Australian astronomy workforce. Nat Astron 5, 615–620. https://doi.org/10.1038/s41550-021-01341-z
2. Sawer, M. 2016, The long slow demise of the Marriage Bar, Inside Story https://insidestory.org.au/the-long-slow-demise-of-the-marriage-bar/
3. Equal Pay Principles of the former Australian Conciliation and Arbitration Commission in the Equal Pay handbook, 1998, p. 20 https://humanrights.gov.au/sites/default/files/content/pdf/sex_discrim/equal_pay.pdf
4. Stevenson, T. 2023, Melbourne Observatory’s Astrographic Women: Star Measurers and computers, JAHH, 26 (2), 325-338. https://dds.sciengine.com/cfs/files/pdfs/view/1440-2807/8D62FF4D393548369EFA51DDFC272A54.pdf
5. As above.
6. Wood, H 1971, Astrographic Catalogue: 1900, vol. LIII, IAU.p. 463
7. Interview with Winsome Bellamy, T. Stevenson thesis, 2015, The University of Sydney, http://hdl.handle.net/2123/15762
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