Lalande, Amélie Lefrançais de (fl. 1790)

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Lalande, Amélie Lefrançais de (fl. 1790)

French astronomer. Name variations: Mme Lefrançais de Lalande. Born Marie Jeanne Amélie Harlay; married Michel Jean Jérôme Lefrançais de Lalande (1776–1839, an astronomer); children: Caroline Lefrançais de Lalande (b. 1790); Isaac Lefrançais de Lalande.

French astronomer Amélie Lefrançais de Lalande worked as an assistant to her husband Michel Lefrançais de Lalande and his cousin Joseph Jérôme Lefrançais de Lalande (1772–1807), who served as Michel's mentor. Although it is difficult to separate her contributions from those of her husband and his cousin, Amélie is credited with calculating the astronomical tables for several publications. She is known to have constructed the tables appended to Jérôme's Abrégé de navigation (1793), which were designed to assist navigators in calculating time at sea, and to have performed the calculations and reductions included in an astronomical almanac he edited, Connaissance des temps.

The names of the Lalande children also reflect the family preoccupation with astronomy. Their daughter Caroline was named after Caroline Herschel who discovered a comet that first became visible in Paris on the day of Caroline's birth (January 20, 1790), and their son Isaac was named after Sir Isaac Newton.

Barbara Morgan , Melrose, Massachusetts