On this day in 1605 - September 28th - French astronomer and mathematician Ismaël Bullialdus was born.

Often regarded as ‘the most noted astronomer of his generation’ he wrote several books, the most famous being Astronomia Philolaica, in which he supported Johannes Kepler’s elliptical planetary orbits. Bullialdus was also a defender of the views and ideas of Copernicus and Galileo.