an Entity references as follows:
Vera Florence Cooper Rubin (/ˈruːbɪn/; July 23, 1928 – December 25, 2016) was an American astronomer who pioneered work on galaxy rotation rates. She uncovered the discrepancy between the predicted and observed angular motion of galaxies by studying galactic rotation curves. Identifying the galaxy rotation problem, her work provided the first evidence for the existence of dark matter. These results were confirmed over subsequent decades.