27 June

1767: On 27 June 1767, Alexis Bouvard was born.

Bouvard was a French astronomer and director of the Observatoire de Paris, who is noted for discovering eight comets and writing Tables astronomiques of Jupiter and Saturn (1808), and of Uranus (1821).

Bouvard's tables accurately predicted orbital locations of Jupiter and Saturn, but his tables for Uranus failed, leading him to hypothesise that irregularities were caused by an unknown perturbing body.

This spurred observations leading to the discovery of Neptune by Adams and Leverrier.