Annie Jump Cannon cover

Annie Jump Cannon

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If you've never heard of Annie Jump Cannon, prepare to be amazed. She was an outstanding scientist whose research helped shape contemporary astronomy. She was honored with numerous awards for her work at Harvard College Observatory, and In numerous cases, she was the first woman ever to do so.

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Annie Jump Cannon

Annie Jump Cannon (1863-1941)

Cannon was born in Dover, Delaware on December 11, 1863, to Wilson Cannon, a shipbuilder, and his wife, Mary.

Not much is known about Cannon’s early education, but it was her mother who introduced her to her first star constellations and encouraged her curiosity in astronomy. Together, they even built a small observatory in the attic of their house.

Cannon attended Wellesley College in Massachusetts, where she studied physics and astronomy under Sarah Frances Whiting. Whiting later introduced her to the director of the Harvard College Observatory, Edward Charles Pickering.

Annie Jump Cannon

Mrs. Annie Jump Cannon, head-and-shoulders portrait, left profile. Library of Congress

Annie Jump Cannon

After Cannon graduated in 1884, she traveled home to Delaware where she contracted scarlet fever, an illness that permanently damaged her hearing.

Return To Wellesley

She remained with her family until her mother’s death in 1893, after which she returned to Wellesley to take graduate classes and to assist Professor Whiting with a physics course.

In 1895 Cannon enrolled in an astronomy course at Radcliffe College, the women’s school associated with the all-male Harvard College in Cambridge, Massachusetts.

She began to spend much of her free time at the Harvard Observatory where she studied the night sky through both telescopes and Harvard’s collection of glass plate photographs. Unusually for that time, the observatory employed several women including Williamina Fleming and Antonia Maury, who were creating a gigantic survey of the stars for the observatory’s director, Edward Pickering.

Edward Charles Pickering

Unknown (Mondadori Publishers)

Edward Charles Pickering

Pickering openly hired women, believing them to be better at the work than the men he had previously appointed. He thought women were more patient, better with details and had smaller hands to handle the necessary equipment. Unfortunately, he also admitted that contracting women was cheaper than hiring men to do the same work.

Stellar Spectra

After her course at Radcliffe ended in 1896, Cannon gave up her position at Wellesley and joined the Harvard Observatory while working on a degree from Radcliffe, which she earned in 1898.

The women at the Harvard Observatory, known collectively as the “Harvard Computers,” studied glass plate photographs that displayed stellar spectra.

These photographs were created by using a spectroscope, a device that translates the light from stars into a spectrum, like a rainbow, which is then captured through a camera and preserved on the glass photographic plates.


These images were called “spectrograms” and the patterns they revealed gave scientists clues as to how big, hot, and fast each star was.

When Cannon joined the Computers she began a project of analyzing these stars and grouping them based on their specific characteristics. She refined a classification system earlier used by Fleming that organized the stars by hottest to coolest using, the letter designations O, B, A F, G K M (with the mnemonic “Oh, Be A Fine Girl, Kiss Me!).

The Harvard Computers

New England Magazine

The Harvard Computers

The Harvard College Observatory was known for the women it employed to classify stellar spectra. Among those shown in this 1892 photograph are Henrietta Leavitt (third from left), Mina Fleming (standing), and Annie Cannon (far right).

Spreading Her System

By 1910, her system was widely used by astronomers, and this work became the core of the Henry Draper Catalogue, an expansive list of over 225,000 spectroscopic stars.

Mary Anna (Palmer) Draper funded the cataloguing project in honor of her deceased husband Henry Draper. The list was issued in multiple volumes between 1918 and 1924, with additions printed in 1925 and 1949. In 1910, the International Solar Union decided that Cannon’s system of classification should become the official system for all observatories.

With a few slight modifications over the years, the Harvard spectral classification system is still used today. To Cannon, the study of stellar spectra wasn’t just a job; rather she believed “each new spectrum is a gateway to a wonderful new world.”


The Harvard Computers didn’t just study spectra on glass plate photographs, they also conducted other investigative research projects, such as documenting variable stars, whose brightness changes over a period of time. Cannon published a catalogue of these curiosities in 1903 and a second one in 1907.

Because of her amazing work, in 1911 Pickering wrote to Harvard’s president, Abbott Lawrence Lowell, requesting that the Harvard Corporation appoint Cannon as Curator of Astronomical Photographs. Lowell declined, but instead suggested Pickering himself appoint her, a less formal option.

He also refused to allow Cannon’s name to appear in the University’s catalogue like all other Corporation appointees.

Hard At Work

Hard At Work

Annie Jump Cannon at her desk at the Harvard College Observatory

The New Curator

Despite the slight, Cannon became the new curator in 1911 and held the position for 27 years.

Her duties included the care of the collection and the execution of any astronomical investigations that Pickering assigned. It wasn’t until 1938 that Cannon received the official university appointment she deserved.

In 1936, despite being 73, Cannon undertook the study of 10,000 very faint stars, at the special request of the Royal Observatory of the Cape of Good Hope.

True Leader

Before her retirement in 1940, she had not only produced her star catalogues, but had also discovered 300 variable stars, five new stars, and one spectroscopic binary.

She died from heart disease on April 13, 1941.

Annie Jump Cannon was an outstanding scientist whose research helped shape contemporary astronomy. Harlow Shapley, the director of the Harvard College Observatory at the time of Cannon’s death, said she was “one of the leading women astronomers of all time.”

Awards and Merits

Image credit: Harvard College Observatory, 1925

Awards and Merits

Annie Jump Cannon won a multitude of awards and honors for the work she conducted at the Harvard College Observatory.

In many cases, she was the first woman ever to do so.

She was the first woman officer of the American Astronomical Society, the first woman to win the Henry Draper Medal of the National Academy of Sciences (1931), the first woman to be elected an honorary member of the British Royal Astronomical Society and the first woman to be awarded an honorary degree by Oxford University (1925).

10,000th Variable Star

In 1938 she was named the William Cranch Bond Astronomer at Harvard University.

In 1932 she was awarded the final Ellen Richards research prize of the Society to Aid Scientific Research by Women for which she was granted $2,000. She turned the money over to the American Astronomical Society to establish the Annie Jump Canon Prize for women astronomers, an award given every third year. The first to receive this prize was her colleague from the Harvard College Observatory, Cecilia Payne-Gaposchkin.

In July 1939, Annie Jump Cannon discovered Harvard’s 10,000th variable star. Both a lunar crater and an asteroid were named for her.

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