Antonia Caetana de Paiva Pereira Maury (March 21, 1866 – January 8, 1952) was an American astronomer who was the first to detect and calculate the orbit of a spectroscopic binary. She published an important early catalog of stellar spectra using her own system of stellar classification, which was later adopted by the International Astronomical Union. She also spent many years studying the binary star Beta Lyrae. Maury was part of the Harvard Computers, a group of female astronomers and human computers at the Harvard College Observatory. Dorrit Hoffleit described Maury as an "independent Renegade", suffering at the Observation for her Independence not agreeing with the way Edward Charles Pickering had them working for minimal credit.
Antonia Maury was awarded the Annie Jump Cannon Award in Astronomy in 1943. William Wilson Morgan, one of the developers of the MK system of stellar classification, which builds upon her work, has said that he considers Antonia Maury "for me, the single greatest mind that has ever engaged itself in the field of the morphology of stellar spectra." The family fled Portugal for Brazil because of the Napoleonic Wars.
Maury's father was the Reverend Mytton Maury, an amateur naturalist, a direct descendant of the Reverend James Maury and one of the sons of Sarah Mytton Maury. Maury's mother was Virginia Draper, a daughter of Antonia Caetana de Paiva Pereira Gardner and Dr. John William Draper.
As a result of their family connections, Antonia and her two siblings were exposed to science at a very early age.
Antonia Maury attended Vassar College, graduating in 1887 with honors in physics, astronomy, and philosophy. At Vassar she studied under the tutelage of renowned astronomer Maria Mitchell.
In 1887, Edward Charles Pickering had found the first spectroscopic binary or double star, ζ<sup>1</sup> Ursae Majoris (Mizar A). Maury was asked to determine its orbit, which she did using periodic doubling of some of the lines in its spectrum. Then, in 1889, Maury discovered a second spectroscopic binary, Beta Aurigae, and calculated its orbital period.
However, when the first spectroscopic binary and its orbit were more widely reported, the name connected with it was Pickering. The discovery was announced by Pickering in a presentation to the Philadelphia meeting of the National Academy of Sciences on November 13, 1889. The work was described in a paper "On the Spectrum of Zeta Ursae Majoris", which appeared in the American Journal of Science in 1890. In both cases the only mention of Maury was a single line, stating that "a careful study of the results has been made by Miss. A. C. Maury, a niece of Dr. Draper". The sole author credit was given as Pickering.
thumb|350x350px|left|[[Harvard Computers at work, including Henrietta Swan Leavitt (1868–1921), Annie Jump Cannon (1863–1941), Williamina Fleming (1857–1911), and Antonia Maury (1866–1952).]]
In 1888,
The Harvard Observatory staff used an alphabetical system of classification designed by Williamina P. Fleming and Annie Jump Cannon. Maury found their classification system inadequate and developed her own. It was considerably more detailed and included information about temperature and about the width, distinctness, and intensity of spectral lines.
In 1891 Maury left the observatory and started teaching in the Gilman School in Cambridge, Massachusetts. Pickering asked her to return and complete her observations, and she said that she was uncomfortable completing her research if her work was unacknowledged.