annie jump cannon

The Harvard Computers (Hint: They were women, not machines!)

Today is the birthday of Annie Jump Cannon, born December 11, 1863, known as one of ‘Harvard’s Computers’. She is credited along with Edward Pickering as the creator of the Harvard Classification Scheme which remains the foundation of today’s stellar classification system.

One of a dozen women hired by Pickering to do the hard work of identifying, classifying and cataloging hundreds of stellar objects, Cannon distinguished herself as the brightest of the bright and rose finally to a full professorship before her death in 1941. Pickering hired the first of his ‘computers’ in a pique of frustration, noting that his maid could probably do better work than he was getting from his students.  Indeed, he hired his maid, Williamina Fleming, who became the first of his ‘computers’ and quickly distinguished herself. Pickering was pleased enough with her work (and lower wages) that he soon built a team comprised entirely of women to compose the catalog. Cannon was hired a little later to oversee a catalog of the southern skies.  While no eponym celebrates her name, her contribution (along with the remaining group at Harvard) as well as the countless women throughout history to impact science, math, politics and all human endeavor, today we remember and say Happy Birthday. A true gifted scientist and true pioneer, gone but not forgotten. As in most human endeavors, nameless and tireless women support the work of more celebrated men with little or no credit.  Newton said of his work:  ’If I have seen further it is by standing on the shoulders of giants.’  Today we acknowledge that many of those giants were and are women.

Image currently in the public domain courtesy New York World-Telegram and the Sun Newspaper.

Today’s post is for hb-she does twice the work and asks for half the credit.  Our boys are who they are because of her.

#133 Because of Edward Charles Pickering.

Probably because women have been systematically written out of history. 

What astrophysicist Edward Charles Pickering did , assembling a team of female scientists, such as Annie Jump Cannon, Henrietta Swan Leavitt and Cecilia Payne-Gaposchkin, to do the work for him, is known as the harem effect and is a common phenomenon in science history.

We are often taught in history class that while men contributed to creating the world we live in through their inventions, discoveries and conquests, women lived oppressed, shielded lives. In reality, women scientists, leaders and inventors have played an important role in the making of our civilisation, they just haven’t been given credit for it.

Source: Cosmos: A Spacetime Odyssey & ricktimus


Historically accurate props from #SilentSky - this was “the latest technology” in 1900. Glass photographic plates of the stars shipped from Peru to Harvard for Henrietta and her colleagues to analyze and catalogue.

The smaller paddles were also glass and used to judge a stars magnitude by comparison. They called them “spankers” after the “fly spankers” (or fly swatters) they resembled.

Thus, peering into far-away spaces of the heavens, and looking back, as it were, into bygone epochs of time, we find stars composed of the same elements necessary to us today, vibrating in the same rhythm, sending out waves of the same lengths.

Annie Jump Cannon,  from Classifying the Stars

She was the first woman to receive a doctor of astronomy degree, which she received from Groningen University.  She developed the system of classifying stars separating them into spectral classes with the letters O, B, A, F, G, K, M.  This is often remembered with the mnemonic “Oh, Be A Fine Girl, Kiss Me.”   She also has one of the coolest names of any human.

The Harvard Computers was a group of woman who were hired by the director of the Harvard Observatory, Edward Charles Pickering. From 1877 to 1919 he hired around 80 women to serve as human “computers”. They were hired instead of men to process large amounts of astronomical data. Some say these women were chosen because they could be hired for far less than their male equivalents. Whatever the reasoning, one thing is very true… the work of these women often goes unappreciated.

“Edward Charles Pickering (director of the Harvard Observatory from 1877 to 1919) decided to hire women as skilled workers to process astronomical data. Among these women were Williamina Fleming, Annie Jump Cannon, Henrietta Swan Leavitt and Antonia Maury. This staff came to be known as "Pickering’s Harem” or, more respectfully, as the Harvard Computers. This was an example of what has been identified as the “harem effect” in the history and sociology of science.

It seems that several factors contributed to Pickering’s decision to hire women instead of men. Among them was the fact that men were paid much more than women, so he could employ more staff with the same budget.This was relevant in a time when the amount of astronomical data was surpassing the capacity of the Observatories to process it.

The first woman hired was Williamina Fleming, who was working as a maid for Pickering. It seems that Pickering was increasingly frustrated with his male assistants and declared that even his maid could do a better job. Apparently he was not mistaken, as Fleming undertook her assigned chores efficiently. When the Harvard Observatory received in 1886 a generous donation from the widow of Henry Draper, Pickering decided to hire more female staff and put Fleming in charge of them.

As a result of the work of the women “computers”, Pickering published in 1890 the first Henry Draper Catalog, a catalog with more than 10,000 stars classified according to their spectrum. Pickering decided to hire Antonia Maury, a graduate from Vassar College, to reclassify some of the stars. Maury decided to go further and improved and redesigned the system of classification. It was published in 1897, but was largely ignored. Afterwards Pickering decided to hire Cannon, a graduate of Wellesley College, to classify the southern stars. As Maury had done, Cannon also ended up redesigning the classification system of the spectra and developed the Harvard Classification Scheme, which constitutes the basis of the system used nowadays.

Although some of Pickering’s female staff were astronomy graduates, their wages were similar to those of unskilled workers. They usually earned between 25 and 50 cents per hour, more than a factory worker but less than a clerical one.“

~ Wikipedia

From all the stories, one of my personal favorites belongs to Henrietta Swan Leavitt. Pickering had tasked Levitt to study variable stars. What she discovered became an early standard that helped future astronomers.

”… Leavitt noted thousands of variable stars in images of the Magellanic Clouds. In 1908 she published her results in the Annals of the Astronomical Observatory of Harvard College, noting that a few of the variables showed a pattern: brighter ones appeared to have longer periods. After further study, she confirmed in 1912 that the Cepheid variables with greater intrinsic luminosity did have longer periods, and that the relationship was quite close and predictable.

Leavitt used the simplifying assumption that all of the Cepheids within each Magellanic Cloud were at approximately the same distances from the earth, so that their intrinsic brightness could be deduced from their apparent brightness (as measured from the photographic plates) and from the distance to each of the clouds. “Since the variables are probably at nearly the same distance from the Earth, their periods are apparently associated with their actual emission of light, as determined by their mass, density, and surface brightness.”

Her discovery is known as the “period-luminosity relationship”: The logarithm of the period is linearly related to the star’s average, intrinsic luminosity (which is defined as a logarithm of the amount of power radiated by the star in the visible spectrum). In Leavitt’s words, taken from her study of 1,777 variable stars recorded on Harvard’s photographic plates, “a straight line can be readily drawn among each of the two series of points corresponding to maxima and minima, thus showing that there is a simple relation between the brightness of the [Cepheid] variable and their periods”.

The period-luminosity relationship for Cepheids made them the first “standard candle” in astronomy, allowing scientists to compute the distances to galaxies too remote for stellar parallax observations to be useful. One year after Leavitt reported her results, Ejnar Hertzsprung determined the distance of several Cepheids in the Milky Way, and with this calibration the distance to any Cepheid could be accurately determined.

Cepheids were soon detected in other galaxies, such as Andromeda (notably by Edwin Hubble in 1923–24), and they became an important part of the evidence that “spiral nebulae” are actually independent galaxies located far outside of our own Milky Way. Thus, Leavitt’s discovery helped to settled the “Great Debate” on whether the Universe was larger than the Milky Way, and thus changed our picture of the Universe forever.

The accomplishments of the American astronomer Edwin Hubble, who established that the Universe is expanding, were also made possible by Leavitt’s groundbreaking research. “If Henrietta Leavitt had provided the key to determine the size of the cosmos, then it was Edwin Powell Hubble who inserted it in the lock and provided the observations that allowed it to be turned,” wrote David H. and Matthew D.H. Clark in their book Measuring the Cosmos. To his credit, Hubble himself often said that Leavitt deserved the Nobel Prize for her work. Gösta Mittag-Leffler of the Swedish Academy of Sciences tried to nominate her for that prize in 1924, only to learn that she had died of cancer three years earlier (the Nobel Prize is not awarded posthumously).“

~ Wikipedia

I highly recommend reading, "Miss Levitt’s Stars” by George Johnson if you would like to take your experience beyond Wikipedia <3

But don’t just stop there… all of these women deserve your curiosity. if not to learn more about their lives, then to learn about the science they loved.


How Do We Classify The Stars In The Universe?

“Cannon herself was responsible for classifying, by hand, more stars in a lifetime than anyone else: around 350,000. She could classify a single star, fully, in approximately 20 seconds, and used a magnifying glass for the majority of the (faint) stars. Her legacy is now nearly 100 years old: on May 9, 1922, the International Astronomical Union formally adopted Annie Jump Cannon’s stellar classification system. With only minor changes having been made in the 94 years since, it is still the primary system in use today.”

A look up at the stars in the night sky shows a clear distinction: some are fainter while others are brighter, some are redder while others are bluer, some are closer while others are much farther away. But what accounts for the differences – some real and some only apparent – between these stars? For most of human history, not only didn’t we know, but any distinction or classification scheme seemed arbitrary. In the 1800s, a new tool, stellar spectroscopy, enabled us to break up the light from stars into its individual wavelengths. By observing a number of “dark” features in these spectra, corresponding to atoms, ions and their absorption lines, we could finally start to make sense of it, and a more objective system.

The person who piece it all together was Annie Jump Cannon, and her 1901 system is still in use today!

I was really happy with the Cosmos episode tonight because it was pretty much about the contributions to astonomy made by women whose names are not widely known. I’m also really glad that it included the story of a deaf woman, Annie Jump Cannon, and told of her discoveries as well. I love this show so much!! This episode reminded me of “The Lives of the Stars” episode in the 1980 series.

Annie Jump Cannon (1863-1941) was an instrumental figure in world astronomy. She is credited with the co-creation of the Harvard Classification Scheme, the first serious attempt to classify and organize stars based on their temperature.

She was the valedictorian at Wellesley College, one of the top universities for women in the U.S., and graduated with a degree in Physics. She started working at the Harvard College Observatory. Throughout her career which spanned more than four decades, she helped gain the respect and acceptance of the scientific community for women involved in the field.


There is a new picture book about Annie Jump Cannon, class of 1884, who was a superstar in the field of astrophysics. Annie personally identified more than a quarter of a million stars and, in 1923, was recognized as one of the 12 greatest women living in America.

anonymous asked:

*is chaotic good* TOMATO *giggles wildly to self* (a favorite quote?)

I love a good homegrown tomato tbh.

Honestly at this point in time it’s the one I posted from Annie Jump Cannon: “In these days of great trouble and unrest, it is good to have something outside our own planet, something fine and distant and comforting to troubled minds. Let people look to the stars for comfort.”