As we continue to learn about Henrietta’s
research, we see she produced numerous advances in the field. Henrietta
discovered a means to not only identify, but rank the magnitudes of stars using
photographic plates. Henrietta discovered a way by which astronomers became
better able to accurately measure extra galactic distances known as the
period-luminosity relation. She also discovered more variable stars than any
other astronomer of her time.
Pickering soon promoted Henrietta
to department head of the photographic photometry (science of measuring the
brightness of stars). In 1912, Henrietta, by comparing different photographs of
the same variable star, especially those stars of the “Cepheid” type that had
bright-dim cycle periods, established that the slower the blink time the more
light or brightness the star contained.
The Cepheid research excited Henrietta,
but Pickering hired her to do a specific job, and would not allow her or the
other “computers” to veer from their assigned tasks. Cecilia Payne-Gaposchkin,
who never knew Leavitt, felt that by not giving Henrietta full rein to explore
her passion for variable stars, “condemned a brilliant scientist to uncongenial
work, and probably set back the study of variable stars for several decades.”1
“…it ruthlessly relegated Miss
Leavitt to the drudgery of fundamental photometry when her real interest lay in
the variable stars that she had begun to discover in the Magellanic Clouds.”2
"What a
variable-star 'fiend' Miss Leavitt is," wrote Charles Young of Princeton
in a letter to Pickering. "One can't keep up with the roll of the new
discoveries."3
One of Henrietta’s
discoveries concerned the redness of stars. She found that fainter stars were
usually redder than brighter ones. This led her to question “whether the light
was possibly reddened by interstellar absorption.”4
1George Johnson. Miss Leavitt’s Stars: The Untold Story of
the Woman Who Discovered How to Measure the Universe. (New York: W. W.
Norton & Co., 2005), 91.
2Cecilia
Payne-Gaposchkin. Cecilia Payne-Gaposchkin: an Autobiography and other
Recollections. (Great Britain: Cambridge University Press, 1984), 145.
3http://www.encyclopedia.com/topic/Henrietta_Leavitt.aspx
(accessed January 20, 2015).
4Harry G. Lang, Bonnie Meath-Lang. Deaf Persons in
the Arts and Sciences: A Biographical Dictionary. (Westport, Connecticut:
Greenwood Press, 1995), 221.