Antonia Caetana de Pereire Maury was born in Cold Spring, New York, on March 21, 1866.
She was the daughter of Reverend Mytton Maury, a protestant minister and naturalist, and Virginia Draper Maury. Antonia
was descended from distinguished teachers and scientists. Her father's
great-grandfather, Reverend James Maury, was the teacher of three
American presidents—Thomas Jefferson, James Madison, and James
Monroe—and she was the granddaughter of John William Draper and the
niece of Henry Draper, both prominent physicians and pioneering
astronomers in celestial photography. In fact, in 1840 her grandfather
had made the first daguerreotype image of the moon and in 1872 her uncle
made the first photograph of a star, Vega, showing absorption lines.
Antonia was introduced to scientific study early on. At the age of four,
she was reputed to have helped her uncle in his laboratory by handing
him the test tubes he asked for in his chemical experiments.
Antonia
attended Vassar college to receive her higher education. The college
requires 24 semester courses and of these, Antonia took 8 semesters of
astronomy. She graduated in 1887 with honors in physics, astronomy, and
philosophy. After graduating, Maury got a job at the Harvard College
Observatory cataloging, or organizing stars according to a color index
developed by Fleming, who was in charge of the cataloging process. She
was a “computer” responsible for computing and cataloging stellar
spectra for bright stars in the northern hemisphere. This required
analyzing thousands of spectral photographs for minute differences. The
average pay for women at this time was 25 cents an hour, less than half
the amount paid to men. Maury was dissatisfied with both her pay and the
system that she had to follow, so she devised her own; one that had 22
groups in a sequence of descending temperature that classified many
stars that the Fleming system could not classify. There was also a
concurrent scheme which specified the width and distinctiveness of the
lines. A lines were wide and well defined, B lines were hazy but
relatively wide and of the same intensity as A, and C were spectra in
which the hydrogen lines and helium (formerly known as “orion lines”)
lines were narrow and sharply defined but the calcium lines were more
intense. She also had a class called AC stars for stars having
characteristics of both classes.
Maury’s individual work was not appreciated by Pickering, who was in
charge of the operation. Her own theoretical work, he argued, not only
interfered with her status of being a “computer”, but also slowed down
the work on the Draper Catalogue they were trying to complete. Pickering
became more and more constrictive and gave Antonia less and less
freedom until in 1891, when she quit to teach at Gilman School in
Cambridge.
Although Maury's stellar spectra criteria were never adopted for the
Harvard project, the Danish astronomer and chemist, Ejnar Hertzsprung,
came to recognize their value. He said, "In my opinion the separation of
Antonia C. Maury of the c- and ac- stars is the most important
advancement in stellar classification since the trials by Vogel and
Secchi. To
neglect the c-properties in solar spectra, I think, is nearly the same
thing as if the zoologist, who had detected the deciding differences
between a whale and a fish, would continue in classifying them
together." By 1913, Hertzsprung and another astronomer named Henry
Norris Russel had independently created what is known as the
Hertzsprung-Russel diagram, a plot using absolute magnitude, luminosity,
classification, and effective temperature of the stars. This new way of
plotting magnitude and luminosity against temperature is considered the
key to modern stellar evolution theory. In 1922, the system of
including the prefix c- to a certain spectral type was adopted by the
International Astronomical Union.
For the rest of her life, Maury worked only on and off with Harvard.
She taught at the Castle School in New York from 1896 to 1918 and
returned to Harvard at the end of 1918. The next year Pickering died and
found herself able to work better with his successor, Harlow Shapley.
She continued to research spectroscopic binary stars over the next
couple years. She retired to long-established interest. She fought for
conservationist and naturalist causes, such as when she fought to save
western Sequoia forests that were endangered by wartime lumber
requirements. She died January 8, 1952 in Dibbs Ferry, New York, a
brilliant researcher and distinguished astronomer.
