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Nicole-Reine Lepaute, mathematician and astronomer of the 18th century, contributed to predicting the return of Halley's Comet.
Nicole-Reine Hortense Étable de la Brière Lepaute (1723-1788) is an emblematic figure of French astronomy in the 18th century. Born in Paris, at the Luxembourg Palace, where her father was in the service of Marie-Louise-Élisabeth de Bourbon-Orléans, she grew up in an environment conducive to education and intellectual curiosity.
Birth record of Nicole Reine Etable - Paris Archives
In 1749, she married Jean-André Lepaute, clockmaker to the king, and was actively involved in her husband's work, particularly in calculating pendulum oscillation tables for a clockmaking treatise.
Her encounter with the astronomer Jérôme de Lalande, who had installed his astronomical equipment at the Luxembourg Palace, marked a turning point in her scientific career.
In 1757, alongside Lalande and mathematician Alexis Clairaut, Nicole-Reine Lepaute undertook complex calculations to predict the return of the comet of Halley.
For nearly a year, she worked tirelessly to determine the gravitational perturbations of Jupiter and Saturn on the comet's trajectory.
Their prediction placed the comet's passage on April 13, 1758, a remarkable estimate given the tools of the time, although the comet actually passed on March 13.
Despite her crucial role, her name does not appear on the list of Clairaut's assistant calculators, probably for social reasons related to the time. However, her work is recognized by her peers, notably by Jean-Baptiste Delambre, who highlights her essential contribution to the task of predicting the comet's return.
Subsequently, Nicole-Reine Lepaute collaborated with Lalande to produce ephemerides, notably for the 1761 transit of Venus, a major event involving many astronomers.
She also wrote memoirs for the Royal Academy of Béziers, which elected her as an associate member in recognition of her contributions.
In 1764, she precisely calculated the annular solar eclipse of April 1st, publishing a detailed map of the eclipse's progression across Europe. This work was published in the "Mémoires de Trévoux," demonstrating once again her expertise in astronomy.
The life and work of Nicole-Reine Lepaute illustrate the essential role that women have played, often in the shadows, in the development of science.