WoW Blog (Woman of the Week) Blog

WoW Blog (Woman of the Week)

Each week this blog will feature a prominent woman who made significant contributions to engineering or science. If you have any women you'd like us to feature please let us know and we'll do our best to include them.

Do you know of a great woman in engineering that should be recognized? Let us know! Submit a few paragraphs about that person and we'll add her to the blog. Please provide a citation for the material that you submit so that we can verify it. Please note - it has to be original material. We cannot publish copywritten material or bulk text taken from books or other sites (including Wikipedia).

Previous in Blog: Dorothy H. Andersen: First Physician to Recognize and Diagnose Cystic Fibrosis   Next in Blog: Edith Clarke: First American Female Electrical Engineer
Close
Close
Close
2 comments

Henrietta Leavitt: "The Brightest Woman at Harvard"

Posted July 26, 2012 12:00 AM by SavvyExacta

Henrietta Leavitt discovered more than 2,400 variable stars while working at the Harvard College Observatory. Despite being deaf and the era's prejudices against women, which prevented Leavitt at first from being paid and later pursing her own topics of study, she developed the Harvard Standard of photographic measurements.

Leavitt was born on July 4, 1868 in Lancaster, Massachusetts. She studied astronomy in 1892, during her final year of college. The following year she began unpaid work as a volunteer at the Harvard College Observatory. Her first job was as a "computer" measuring and counting stars in photographic plates. Seven years later she became a paid employee earning $10.50 per week.

Unable to use telescopes because she was a woman, Leavitt used photographic plates to measure the magnitude of variable stars. (Variable stars have a change in apparent magnitude as seen from the Earth caused by swelling and shrinking, or light being blocked from reaching the Earth. Cepheid variable stars are very luminous.)

In 1908, some of Leavitt's findings related to her study of variable stars in images of the Magellanic Clouds were published in the Annals of the Astronomical Observatory of Harvard College:

  • Brighter variable stars appeared to have longer periods
  • Stronger stars appeared to have slower cycles
  • The cycles of variable stars depend on how bright they really are (intrinsic luminosity)
  • Cepheid variable stars in the Small Magellanic Cloud are all about the same distance from the Earth
  • A period-luminosity ratio could be used to measure the distance from Earth to any Cepheid star

Leavitt developed a standard of photographic measurements called the Harvard Standard that was accepted by the International Committee of Photographic Magnitudes. She used hundreds of photographic plates and logarithmic equations to order stars according to magnitudes of brightness.

Others used Leavitt's formula to further their own studies:

  • Ejnar Hertzsprung plotted the distance of stars
  • Harlow Shapley measured the size of the Milky Way
  • Edwin Hubble ascertained the age of the Universe

Hubble said Leavitt deserved a Nobel Prize for her work; she died of cancer on December 21, 1921 before she could be nominated. A colleague considered her "the brightest woman at Harvard." An asteroid and a crater on the moon have been named for her.

Resources:

CWP - Henrietta Swan Leavitt

MIT - Henrietta Leavitt (1868-1921)

She is an Astronomer - Henrietta Leavitt (1868-1921)

Wikipedia - Henrietta Swan Leavitt

Wikipedia - Variable star

The Woman Astronomer - Henrietta Swan Leavitt - Lady of Luminosity

http://www.physics.ucla.edu/~cwp/Phase2/Leavitt,_Henrietta_Swan@871234567.html

http://www.aas.org/cswa/status/2005/JANUARY2005/HenriettaLeavitt.html [image 1]

http://ottawa-rasc.ca/features/marchHubble/leavitt-graph.gif [image 2]

Reply

Interested in this discussion?
You can "subscribe" to this discussion to be notified of new comments.
Click on the Subscribe menu at the top of the page.
Guru
Engineering Fields - Optical Engineering - Member Engineering Fields - Engineering Physics - Member Engineering Fields - Systems Engineering - Member

Join Date: Apr 2010
Location: Trantor
Posts: 5363
Good Answers: 646
#1

Re: Henrietta Leavitt: "The Brightest Woman at Harvard"

07/26/2012 7:39 AM

Overall, this is a good article about a woman astronomer who made a major contribution to science and deserves to be remembered. (I'd make a few changes to the article, as for example, I have no idea what is meant by a 'stronger' star, a term I've never heard before; plus the list of properties of Cepheid variables is somewhat redundant.) The important point though, is that her work on Cepheid variables was a major discovery leading to our understanding of the distance scale of the universe. The Period-Luminosity relationship of Cepheid (and RR Lyrae-type) variables allowed other astronomers to measure the distances to the nearest galaxies, and was thus a key 'yardstick' in measuring the universe.

Among all the sciences, Astronomy is noted for having a number of women making important discoveries and contributions in the 19th and 20th centuries, when the other sciences were almost completely dominated by men. A few names come quickly to mind such as Caroline Herschel, Annie Cannon, Williamina Stevens, Cecelia Payne, Margaret Burbidge, Carolyn Shoemaker and Jocelyn Bell.

__________________
Whiskey, women -- and astrophysics. Because sometimes a problem can't be solved with just whiskey and women.
Reply
Guru
Engineering Fields - Optical Engineering - Member Engineering Fields - Engineering Physics - Member Engineering Fields - Systems Engineering - Member

Join Date: Apr 2010
Location: Trantor
Posts: 5363
Good Answers: 646
#2

Re: Henrietta Leavitt: "The Brightest Woman at Harvard"

07/26/2012 7:54 AM

Just as a follow-up: for years no Nobel prizes were awarded for work in Astronomy, despite many important discoveries. Even Hubble himself did not win it. Only in 1978 was a Nobel awarded (in Physics) to Penzias and Wilson, for their work at Bells Labs in the 1960s when they discovered the 3 K background radiation left over from the 'Big Bang'. Since then a few other Physics Nobels have gone to astronomers, including last years' Physics prize that went to 3 astronomers for their work on Dark Energy and the expansion of the universe.

__________________
Whiskey, women -- and astrophysics. Because sometimes a problem can't be solved with just whiskey and women.
Reply
Reply to Blog Entry 2 comments
Interested in this discussion?
You can "subscribe" to this discussion to be notified of new comments.
Click on the Subscribe menu at the top of the page.

Previous in Blog: Dorothy H. Andersen: First Physician to Recognize and Diagnose Cystic Fibrosis   Next in Blog: Edith Clarke: First American Female Electrical Engineer

Advertisement