Beatrice Tinsley

Beatrice attended New Plymouth Girls’ High School, where she excelled in all academic subjects, and music, playing the piano and violin. She was dux of her school in 1957 and was one of only 10 students to win a Junior University Scholarship.

Beatrice studied a BSc in physics at the University of Canterbury, having decided she wanted to become a cosmologist. She graduated in 1961, the same year she married her husband, Brian Tinsley, a postgraduate student in physics, and they settled in Christchurch. Beatrice’s cosmology ambitions in Aotearoa New Zealand were thwarted due to a lack of appropriately qualified supervisors, so she settled on doing her master’s thesis on a solid-state physics project. She completed it in 1962, winning all of the prizes available for her year.

Despite her brilliance, Beatrice was also a victim of her gender. After her marriage, she was barred from working at the university while her husband was employed there. In 1963, they moved to Dallas, Texas, so Brian could take up a role at the Southwest Centre for Advanced Studies – later known as the University of Texas, Dallas (UTD). Again, Beatrice was unable to obtain a faculty position at the University of Texas at Dallas, in part because her husband worked there.

Instead, in 1964, Beatrice enrolled in a PhD in astronomy under Dr Ranier Sachs at the University of Texas at Austin (UTA), which was over 300 kilometres away. She commuted to Austin and completed her PhD in two years, receiving marks of 99 and 100 per cent. She and Brian adopted a son, Alan, in 1966, and Beatrice then had to juggle motherhood with writing her thesis. She passed her oral exam in December that year, with her thesis entitled ‘Evolution of galaxies and its significance for cosmology’. Beatrice and Brian would adopt a second child, Teresa, in 1968, and divorce in 1974.

On the total scale of things, a galaxy is the biggest known ‘thing’. The current model of the universe has it being made up of hundreds of millions of island galaxies, where a galaxy is a collection of hundreds of millions of stars, some with solar systems like our own.

Beatrice’s work was on the development of these galaxies and of the stars within. She asked, ‘How did they form?’ She created models of galactic and star formation that were more realistic than other models at the time, combining a detailed understanding of stellar evolution with knowledge of the motions of stars and nuclear physics, and collaborated with astrophysicists and cosmologists all over the world. Together, they showed that the universe would not collapse in on itself but would expand forever, an advance in cosmology that also received wider general publicity.

Beatrice delighted in explaining her science to a non-scientific audience, presenting evidence in terms that were easy to understand. She married together many branches of knowledge and created a workable model of galactic evolution.

Her work had a profound effect on the study of astrophysics at the time, changing the direction of thinking on galactic formation. Beatrice went on to become the first female professor of astronomy at Yale University in 1978, but, sadly, she was diagnosed with cancer the same year, and passed away three years later, aged 40. Beatrice continued to work right up until her death, publishing 10 papers, including a 100-page review paper.

Throughout her life Beatrice authored over 100 scientific papers; she was heralded as a great scientist and teacher, and an inspiration to women scientists both in America and New Zealand.

In her honour, the American Astronomical Society established the Beatrice M Tinsley Prize for outstanding creative contributions to astronomy or astrophysics. This award, available since 1986, is the only major award honouring a woman scientist to be created by an American scientific society.

Beatrice Tinsley is now rightly recognised as one of New Zealand’s most important scientists. Her work inspired a number of awards and endowments, but, perhaps more permanently, she has a mountain and an asteroid named after her. Mt Tinsley, at 1537m, is in the Kepler Mountains in Fiordland – Kepler was also an astronomer. The main-belt asteroid 3087 Beatrice Tinsley (1981 QJ1) was discovered in 1981 at the Mt John University Observatory near Tekapo.

Beatrice Tinsley was known as the ‘Queen of the Cosmos’, and her work was described by her biographer, Christine Cole Catley, as “opening doors to the future study of the evolution of stars, galaxies and even the Universe itself”.