DOVER, DE- The legacy of Annie Jump Cannon, a pioneering Dover native who revolutionized stellar classification, is being remembered today. Cannon, born 161 years ago on this day in 1863, made groundbreaking contributions to astronomy and to women in science.
Annie Jump Cannon (1863–1941) was an American astronomer whose transformative work in stellar classification changed the way astronomers understand the stars. She developed a system that classified stars based on their spectra, with a focus on their color and temperature.
This system, known as the Harvard Classification Scheme, is still used by astronomers today and remains one of her most enduring contributions to the field.
Stephen Marz, with the Delaware Public Archives, discussed the lasting impact of Cannon’s work on the field of astronomy.
“She observed and classified over 300,000 stars based on color and temperature. Her work was so rewarding that she actually received an honorary Ph.D. from Oxford."
Marz noted that her interest in astronomy blossomed early here in Dover and never wavered.
“She became interested in the stars when she was a young child. She lived right here in Dover, down on South Street, and would begin her initial observations of stars on the roof of her home.”
Cannon’s passion for astronomy continued as she attended Wellesley College and the Women’s College at Harvard University. However, her journey was not without challenges.
As a woman in a male-dominated field, Cannon faced significant obstacles. She also contended with a hearing disability, which further complicated her path.
Annie Fenimore, with the Delaware Division of Historical and Cultural Affairs, highlighted Cannon's steadfast commitment to astronomy despite facing significant personal and professional challenges.
“Not only was her gender a limitation, but so was her hearing disability. When she was working at the Harvard Observatory, there was the issue of people not wanting to promote her — and by people, I mean men,”
Despite these barriers, Cannon’s contributions have had a lasting effect on astronomy.
Outside her childhood home in Dover, a historical marker honors her legacy, allowing the community to reflect on her accomplishments—not just on her birthday, but every day.
Her stellar classification system, which is still in use today, continues to shape the study of the stars, solidifying her place in history.
