Delisle apparently later changed his mind and announced the discovery on 1 April 1759, but other French astronomers discredited Delisle's claim, labelling the discovery an April Fools' joke. Delisle retired in 1760.
Delisle eventually reversed himself and announced the discovery on April Fool's Day, 1759; however, other French astronomers dismissed his assertion as a prank. Delisle left his position in 1760.