Annie Jump Cannon
The Lady Who Counted the Stars
In the Old Testament of the Bible, when God told Abraham the patriarch that he would have a son and then numerous descendants he used an interesting image. The Bible describes it: “And I will make thy seed [descendants] to multiply as the stars of heaven…” (Genesis 26:4a KJV) In other words, Abraham’s descendants—the Jews—were to be uncountable—just as the stars we see on a clear night might seem to be. That also included the stars we couldn’t see.
So how many stars are there? Astronomers in the ancient world certainly didn’t know, and even today scientists can’t be sure. However, they certainly know much more about the stars than did those in the ancient world—and over the years many scientists have been able to classify them in many ways. One of those who began to organize and classify stars was a woman named Annie Jump Cannon, who was known in her lifetime as “The census taker of the sky.”
Born in December, 1863 in Dover, Delaware, Miss Cannon was the eldest of three girls and the daughter of a Delaware state senator/shipbuilder and his wife. Indeed, it was her mother whose interest in studying the heavens influenced her daughter to an interest in science. In fact, Annie and her mother would often open a trapdoor in their roof to observe the stars, from the small observatory that together they had constructed. It was also her mother who encouraged her daughter to pursue a scientific course of study, so as Annie entered Wellesley College in 1880 she studied math, chemistry and biology. Aside from science, Annie’s mother also instructed Annie in household economics, a subject that she utilized as she organized her later research.
However, when Annie was still young, she began to lose her hearing—possibly from scarlet fever—but this did not hamper her progress in her studies. Also, along the way she decided not to marry and have children.
An important mentor for Annie at Wellesley was a prominent instructor in physics Sarah Frances Whiting. Annie graduated in 1884 as valedictorian of her class. She returned home to Delaware to study photography, and later as she traveled, the pictures she took were published in a book that was offered at the Chicago World Fair.
Then after her mother’s death in 1894 Miss Cannon returned to Wellesley as a junior physics instructor. This allowed her to take graduate courses to further her education, particularly at Radcliffe where she enrolled as a “special student.” She completed her master’s degree in 1907.
Since Radcliffe was the women’s college associated with Harvard, this led to her being employed by the Harvard College Observatory, and even further study. Also in 1896 Cannon had become involved with the Harvard “computers”—women employed by the Harvard Observatory who would examine and classify stars to prepare a catalog. Annie became so adept at this that in 1927 Edward C. Pickering, Harvard Observatory director, said, “Miss Cannon is the only person in the world—man or woman—who can do this work so quickly.”
In fact, according to one source, “When she first started cataloging the stars, she was able to classify 1000 stars in three years, but by 1913 he was able to work on 200 stars an hour. …” She examined the photo of the star and with a magnifying glass determined their magnitude and other aspects to classify them. She also developed a new system to classify stars based mainly on their temperature—a system that is often still used today.
During this period Miss Cannon and her other female associates at the observatory began to be criticized as being “out of their place”—not being homemakers. It was a common complaint of the time, based on tradition and the lack of acceptance, and also meant that women were limited in advancement opportunity and were usually paid just 25 cents an hour for a six day schedule.
Still, for her work and the respect of her associates, Miss Cannon earned several honors. She became the Curator of Astronomical Photographs at Harvard and in 1914 became an honorary member of the Royal Astronomical Society. In fact, she continued to add to the star catalog, by classifying some 350,000 over her lifetime. Then in 1921 she was the first woman to be granted an honorary doctorate from a European university in the fields of math and astronomy.
Apart from her scientific efforts she also worked for women’s rights—particularly the right to vote and as a member of the National Woman’s Party. And in 1923 Miss Cannon was selected as one of the twelve greatest American women by the National League of Women Voters.
Her career in astronomy spanned more than 40 years when she retired in 1941 as a permanent faculty member of the Harvard College Observatory. However, even until her death the next year, Miss Cannon continued to work in her field in the observatory. As one source stated: ”During her career, Cannon helped women gain acceptance and respect within the scientific community. Her calm and hardworking attitude and demeanor helped her gain respect throughout her lifetime and paved the path for future women astronomer.”
Anne Adams is a retired church staffer. She lives in East Texas and has an historical column for a local newspaper. She has published in Christian and secular publications for more than 40 years.