Thursday, April 2, 2009

Henrietta and Cepheid stars

I dunno

There is something in the story of Henrietta that just makes me smile.

Now imagine this. In 1893 a young lady knocks the door of Harvard College Observatory to look for a job.

What can the administration do? Show her the door?

Obviously, this only 25 years old woman had to be smart having graduated with Bachelors degree from the Society for the Collegiate Instruction for Women the year before in 1892. That was quite an achievement for a woman at that time. (Today the place is known as Radcliffe College).

Her character was surely impeccable: as a respectable daughter of a Congregational minister she probably would be a hard worker. And her being deaf might harm her changes to get married but the handicap would probably keep her in the place of work.

But a woman working in an observatory?

(Let us remember that in the pre-feminist world of Victorian England a 19th century gentleman was allowed to punish her spouse but the rod should not be thicker than his little finger.)

Well. To our luck, a very smart man was working at Harvard Observatory. Edward Charles Pickering (1846– 1919) was specialicing in astronomic photography and he suggested that this woman could work with the group of women he had hired to calculate stars on photographic plates. This group was called "Pickering harem" by the scientific community. Probably most of the men in the honourable observatory considered this menial job with photographic plates suitable for the smaller brains of women - and had never heard of suffragettes.

Harvard observatory women were called "computers" and nobody really considered their borgin job all that important. The group included, among others, also Annie Jump Cannon (1863-1941) and Antonia Maury (1866-1952).

Henrietta at work studying the stars

So what is so funny about this?

A deaf girl doing menial job as an assistant among male scientist with their high hats, cigars and comfortable ideas about themselves? Henrietta's salary was just 10.50 dollars a week. Well, she was a woman, after all, wasn't she? Can't give her equal salary with us men doing real important scientific research, can we?

What makes me smile is the fact that most of the guys working with high hats and high salaries have not been heard since.

But this Henrietta.

She made a discovery that was to revolutionize the scientific world. It would not only affect astronomy but totally change the way the human race understands the size and character of the entire universe.

She achieved this amazing result just by looking patiently day after day, month after month, at those stupid photographic plates Pickering and his team was taking about the night sky and by carefully calculating changes in the luminosity of the Cepheid stars seen in them.

As a deaf person she was not disturbed by the noises around her. She did not marry and she staid at her work. During her life time Henrietta was never given credit for her wonderful achievement. In 1921 the faithful worker was rewarded after 28 years of service and the new director, Harlow Shapley, made the head of the department of photometry at Harvard observatory but she succumbed to cancer the same year.

Today she is counted among the top astronomers of modern times and would surely deserve Nobel price.

There is something about the story of Henrietta Swan Leavitt that makes me smile.


  1. jutusta en ihan ymmärtänyt, mikä Henriettan mullistava löytö oli

  2. en kertonut sitä vielä eikä sitä Henriettan työkaverit ja pomot tajunneet. avaruustutkimuksen historia on aika laaja tarina ja etenen askel kerrallaan, jotta saisin vaiheet kunnolla hahmoteltua.
    Seuraava askel eli Mt Wilsonin Hookerin rakentaminen ja Edwin Hubblen tulo sinne ovat nyt menossa - siellä jo pikkusen pilkottaa ensimmäinen Andromeda galaksissa havaittu Cepheid, josta Henriettan havainnot lähtivät aivan huikeaan lentoon.