[1] Also active in astronomy, she determined the orbit of the newly discovered asteroid 267 Tirza while studying at the Leander McCormick Observatory at the University of Virginia.

[1] She had very high standards of education, giving more than half of her students D grades during the first year she taught from her trigonometry book.

[1] In 1888, Hayes wrote a regular column for the Wellesley College newspaper discussing women's suffrage and dress reform, and in the 1890s she founded a chapter of the temperance movement.

[3] A history of Wellesley College reads: A dauntless radical all her days, in the eighties she was wearing short skirts; in the nineties she was a staunch advocate of Woman's Suffrage; in the first two decades of the twentieth century, an ardent Socialist.

[1] Hayes was a controversial figure not just for being one of the rare women among mathematics professors in nineteenth-century America, but for her embrace of radical causes such as questioning the Bible, gender-related clothing conventions, suffrage, temperance, socialism, the 1912 Lawrence Textile Strike, and Sacco and Vanzetti case.

[2] In 1929, she moved to West Park, New York to teach at Vineyard Shore School for women workers in industry, despite her pain from arthritis.