1863-1941

American Astronomer

Annie Jump Cannon was the first astronomer to develop a simple spectral classification system. She classified 400,000 stars—more than anyone else had achieved previously—and discovered 300 variable stars, five novas, and a double star. Cannon was the most famous female astronomer of her lifetime and was called the "Census Taker of the Sky." Cannon's successes inspired other women to pursue astronomical investigations, despite gender biases demonstrated by many male astronomers.

Born on December 11, 1863, in Dover, Delaware, Cannon was the daughter of Wilson Lee and Mary Elizabeth Cannon. Her father served in the state senate. Cannon's mother transformed their attic into an observatory for Cannon to stargaze. At Wellesley College, Cannon studied with astronomer Sarah F. Whiting (1846-1927), who taught her new research methods. After graduating in 1884, Cannon returned home, where she focused on social activities, and traveled, photographing a solar eclipse...