He appeared in northern Italy, in Rome and in Sicily, where he in 1801 at the Observatory of Palermo the first asteroid discovered, Ceres ( first seen as a comet, then classified as a planet, from about 1850 as the largest asteroid ( asteroid ) and since 2006 as a dwarf planet referred to ).
Life and work
Piazzi studied in Turin theology and philosophy. To 1764, he joined the Theatines and became a preacher in Cremona. From 1779 he was professor of theology in Rome and in 1780 professor of mathematics at the Academy in Palermo.
From 1781 he was director, founded with the support of the Viceroy of Sicily from him observatory in Sicily's capital Palermo. When he certain precise star positions in an astrometric project, he succeeded on 1 January 1801, the discovery of the first asteroid in the solar system. He held it first for a distant comet, but realized after a few weeks of a planetary orbit. The nearly 1000 km large celestial body was later named after the Roman earth goddess Ceres. Even before a precise orbit determination he was lost, but was found after an analysis of the young Carl Friedrich Gauss to year end. Since August 2006, ( 1) Ceres the new status of a dwarf planet (along with Pluto and now three other sun distant celestial bodies ).
1808 Piazzi was a foreign member of the Bavarian Academy of Sciences. In 1814 he published a star catalog with 7646 entries. In 1817 he took over the management of the observatory of Naples. He also studied the proper motions of many stars, among others, of 61 Cygni.
The asteroid (1000) Piazzia and the moon crater Piazzi named after him.