Piazzi, Giuseppe(jo͞ozĕp`pā pyät`tsē), 1746–1826, Italian astronomer, a Theatine priest from 1769. He became (1781) professor of mathematics at the Univ. of Palermo, supervised construction of a government observatory (opened 1791) at Palermo, and was its first director. He also established a government observatory at Naples (1817). He was the first to discover (Jan. 1, 1801) an asteroidasteroid,
or minor planet,
small body orbiting the sun. More than 300,000 asteroids have been identified and cataloged; more than a million are believed to exist in the main belt between Mars and Jupiter, with many more in the Kuiper belt
..... Click the link for more information. and named it CeresCeres
, in astronomy, a dwarf planet, the first asteroid to be discovered. It was found on Jan. 1, 1801, by G. Piazzi. He took three distinct observations; on the basis of these the mathematician Gauss calculated Ceres' orbit with such accuracy that it was found one year later
..... Click the link for more information. . In 1803 he published a catalog of the fixed stars, and in 1814 he enlarged it to include 7,646 stars. He wrote Lezioni elementari di astronomia (1817).
Born July 16, 1746, in Ponte di Valtel-lina; died July 22, 1826, in Naples. Italian astronomer.
Piazzi was appointed a professor at the University of Palermo in 1780 and became the first director of the observatory at Palermo in 1791. In 1801 he discovered the first known asteroid —Ceres. He compiled two star catalogs (1803, 1814).