American astronomer Vera Rubin was born on July 23, 1928 in Philadelphia, Pennyslvania. Her interest in astronomy began as a child, and she went to study at Vassar College because she'd read about Maria Mitchell who had taught there. In an interview, she said, “So I knew there was a school where women could study astronomy.”

After graduating with a major in astronomy, she went to Cornell for her masters degree. Her research was in the proper motion of galaxies - motion relative to the expansion of the universe - and she showed that it wasn't random. This was followed up in her PhD work at Georgetown University in Washington DC, in which she was the first to show that galaxies are arranged in groups and large clusters.

Rubin later scored a permanent position at the Carnegie Institution in Washington DC, and began researching the rotation of galaxies in collaboration with Kent Ford. Measuring the redshift / blueshift in different parts of the Andromeda galaxy the data hinted at an oddity in the rotation. The rotational speed didn’t drop off the way it should for a disk made of the visible stars. Their findings were confirmed by studying a number of other spiral galaxies.

She is best remembered for her careful, high-precision observations that provided evidence confirming the existence of dark matter, the mysterious substance that makes up 85% of the Universe’s mass. To many, the discovery of this strange substance deserved a Nobel Prize, but it never happened.

Neta A. Bahcall wrote of Rubin
In spite of the numerous obstacles she faced as a female scientist, Ruben triumphed. She was always cheerful, passionate and persistent. She had wanted to attend graduate school at Princeton University in New Jersey, but was denied because the university did not accept women at the time (Princeton awarded Rubin an honorary degree in 2005). She wanted to use the Hale telescope at the Palomar Observatory in California, but was denied because the facility did not allow women to do so until the 1960s. She paved a path for women not only by encouraging and inspiring them, but also by pressing for them to be hired for faculty positions, to be awarded honours and to be invited to speak at conferences. If too few women were listed as speakers, she would demand that organizers add more. As Vera liked to say, “Worldwide, half of all brains are in women.”

Rubin died in 2016. In December 2019, the Large Synoptic Survey Telescope being built in Chile was renamed the Vera C. Rubin Observatory. It's scheduled to begin scientific operations in 2023. Its ten-year Legacy Survey of Space and Time hopes to “see more of the universe than all previous telescopes combined”.

[Credits: Ian Kemp, Neta A. Bahcall, Sarah Scoles]

Mona Evans
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