Mary Watson Whitney (1847-1921), US astronomer. Whitney was one of the pioneering women scientists of the late 19th century. She was the second director of the Vassar College Observatory, taking over in 1888 from the first director Maria Mitchell, under whom she had studied and for whom she had worked as an assistant. Whitney was also a fellow of the American Association for the Advancement of Science (AAAS) and a member of the Astronomical and Astrophysical Society. She published in many of the leading journals of the day, including the Astronomical Journal and Astronomische Nachrichten. Photograph published in 1922 in the US magazine Popular Astronomy.