Born: 1768, France
Died: 8 November 1832
Country most active: France
Also known as: Marie-Jeanne-Amélie Le Francais de Lalande, Marie-Jeanne Harlay
The following bio was written by Emma Rosen, author of On This Day She Made History: 366 Days With Women Who Shaped the World and This Day In Human Ingenuity & Discovery: 366 Days of Scientific Milestones with Women in the Spotlight, and has been republished with permission.
Marie-Jeanne-Amélie Le Francais de Lalande was a renowned French astronomer and mathematician.
Marie-Jeanne-Amélie Le Francais de Lalande married Michel Lefrançois de Lalande, her father’s young cousin and fellow astronomer, in 1788. She was also the niece of renowned astronomer and writer Jérôme Lalande, who admired her for her strong mathematical aptitude.
Under her father’s guidance, she received instruction in astronomical calculations and observation techniques. She collaborated closely with her father and significantly contributed to his various publications.
Her daughter (born on January 20, 1790) was named after Caroline Herschel, as her birthday coincided with the first appearance of a comet discovered by Herschel in Paris. Her son was named after the renowned physicist and mathematician Isaac Newton.
Marie-Jeanne-Amélie calculated the “Tables horaires de marine,” a publication included in Jérôme Lalande’s “Abrégé de navigation historique théorique et pratique avec tables horaires” in 1793. Her precise calculations earned her recognition and one of the medals from the Lycée des Arts, a distinction for accomplished scholars and artists.
Her work was also featured in her father’s annual almanac from 1794 to 1806. In 1799, she compiled a catalog of 10,000 stars, and she was a collaborator in writing “L’Histoire céleste française,” authored by Lalande and published in 1801. This significant work detailed the positions of 50,000 stars in the celestial sphere.