For the #Spacetober day 11 prompt wavelength: my #linocut of trailblazing US #astronomer Annie Jump Cannon (1863 – 1941) with her stellar classification system which sorted stars based on spectral types, revealing their temperature from hot blue to cool red stars: O,B,A, F, G, K & M. 🐡🧪🔭👩🏼‍🔬 #histsci 🧵 - ThreadSky

minouette.bsky.social • 137 days ago

For the #Spacetober day 11 prompt wavelength: my #linocut of trailblazing US #astronomer Annie Jump Cannon (1863 – 1941) with her stellar classification system which sorted stars based on spectral types, revealing their temperature from hot blue to cool red stars: O,B,A, F, G, K & M. 🐡🧪🔭👩🏼‍🔬 #histsci 🧵

Comments

xryxix.bsky.social•136 days ago

That's so cool

minouette.bsky.social•136 days ago

Thanks!

minouette.bsky.social•137 days ago

Named the Harvard Classification after the university, her tremendous contribution was less visible.

Eldest of 3 daughters of Delaware shipbuilder/state senator Wilson Cannon & Mary Jump, Annie’s mom taught her the constellations & encouraged her to pursue her own interests. She studied physics 🧵2

minouette.bsky.social•137 days ago

with Sarah Frances Whiting, 1 of few US women #physicists at the time, at Wellesley & became valedictorian in 1884. She returned home, worked various jobs, & published her photos over next decade. She lost most of her hearing possibly due to scarlet fever.

When her mom died in 1894 she needed to 🧵

minouette.bsky.social•137 days ago

escape her grief. She wrote Whiting & was hired as junior physics teacher, which allowed her to take grad #physics & #astronomy classes. Harvard astronomer Pickering hired her as assistant in 1896. Running a program to map & catalogue every visible star to photographic magnitude 9, he hired women 🧵4

minouette.bsky.social•137 days ago

(whom he could pay as little as 25 cents/hr for 7 hr/day, 6 days/week) known as Harvard Computers to work on data & catalogue photos. In her first 3 years, she classified 1000 stars. By 1911 she was Curator of Astronomical Photographs & by 1913 she could accurately classify 200 stars/hour! 🧵5/n

minouette.bsky.social•137 days ago

She published her 1st star catalogue in 1901 & finished her MSc at Wellesley in 1907.

Antonia Maury insisted on a complex categorization scheme, to the dismay of manager Williamina Fleming. Cannon negotiated a compromise, dividing stars into spectral classes based on Balmer absorption lines 🧵6/n

minouette.bsky.social•137 days ago

of hydrogen. Nicknamed “Census Taker of the Sky,” she catalogued ~350,000 stars, more than anyone & discovered 300 variable stars, 5 novas & 1 spectroscopic binary.

In 1922, International Astronomical Union formally adopted Cannon’s classification system. 🧵7/8

jopabinia.bsky.social•136 days ago

Our HPC cluster (at Harvard) is named after her!

minouette.bsky.social•136 days ago

Oh cool!

chassmith.bsky.social•135 days ago

I still think she was just messing with everyone when she assigned the labels in the ordering system

minouette.bsky.social•135 days ago

The odd labelling (which predates Cannon) occurred because the spectral classes evolved from an attempt to refine the prior Secchi classification into the Draper Classification.

They broke his Roman numeral classes into alphabetically labelled subgroups which weren’t ordered by temperature.

minouette.bsky.social•135 days ago

Seechi was classifying stars with more of a description of the nature of the spectra, before anyone understood why spectra looked how they did, so as the classification scheme evolved into one based on temperature in Cannon’s scheme, the letters were no longer in alphabetical order.

willcampowell.bsky.social•136 days ago

Love this, though to my shame at first I mistook it for an ad by Radical Tea Towel company.
Thank you for the bio, too.

shaidorsai.bsky.social•137 days ago

I absolutely cannot love this any more than I do. It's gorgeous!

minouette.bsky.social•137 days ago

Thanks very much!

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