Jean-Sylvain Bailly was a French astronomer and politician born on September 15, 1736. He is best known for his work in astronomy, particularly for his studies of the moons of Jupiter and his contributions to the field of celestial mechanics. Bailly was also a member of the French Academy of Sciences and published several important scientific papers. During the French Revolution, Bailly became the first mayor of Paris in 1789. He played a significant role in the early stages of the revolution, advocating for the rights of the people. However, his political career ended tragically when he was executed by guillotine in 1793.