Catholic astronomer. Born Ponte, Italy, 1746; died Naples, Italy, 1826. Joined the Theatine at Milan. Professor of dogmatic theology at Rome in 1779. Professor of mathematics of Palermo in 1780. Director of the observatory at Palermo in 1791. Discovered the first planetoid Ceres on January 1, 1801. Published star catalogues in 1803,1814 that include about 7000 fixed stars. Director of the observatory at Naples in 1817.