Annibale Riccò (14 September 1844 – 23 September 1919) was an Italian
astronomer
An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...
.
Biography
He was born in
Milan
Milan ( , , ; ) is a city in northern Italy, regional capital of Lombardy, the largest city in Italy by urban area and the List of cities in Italy, second-most-populous city proper in Italy after Rome. The city proper has a population of nea ...
, Italy. In 1868 he was awarded a bachelor's degree from the ''
Università di Modena'', then an engineering degree from the ''
Politecnico di Milano''. Between 1868 and 1877 he worked as an assistant at the
Modena
Modena (, ; ; ; ; ) is a city and ''comune'' (municipality) on the south side of the Po Valley, in the Province of Modena, in the Emilia-Romagna region of northern Italy. It has 184,739 inhabitants as of 2025.
A town, and seat of an archbis ...
Observatory, teaching mathematics and physics at the ''Università di Modena''. He taught at
Naples
Naples ( ; ; ) is the Regions of Italy, regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 908,082 within the city's administrative limits as of 2025, while its Metropolitan City of N ...
and then
Palermo
Palermo ( ; ; , locally also or ) is a city in southern Italy, the capital (political), capital of both the autonomous area, autonomous region of Sicily and the Metropolitan City of Palermo, the city's surrounding metropolitan province. The ...
, where he also worked at the observatory.
In 1890 he was named to the chair of astrophysics at the
Università di Catania, and became director of the observatory on
Mount Etna
Mount Etna, or simply Etna ( or ; , or ; ; or ), is an active stratovolcano on the east coast of Sicily, Italy, in the Metropolitan City of Catania, between the cities of Messina, Italy, Messina and Catania. It is located above the Conve ...
as well as the first director of the Catania Observatory. Between 1898 and 1900 he was named chancellor of the university.
During his career he performed research into
sunspots, and he participated in four
solar eclipse
A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season i ...
expeditions, leading the expeditions in 1905 and 1914. He was president of the ''Società degli Spettroscopisti Italiani'' and the ''Gioenia di Scienze Naturali di Catania''. He also served as vice president of the
International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...
. He was elected President of the
volcanology section of the
International Union of Geodesy and Geophysics (IUGG) for the period 1919–1922.
Legacy
He discovered
Ricco's Law, an important principle of
vision science
Vision science is the scientific study of visual perception. Researchers in vision science can be called vision scientists, especially if their research spans some of the science's many disciplines.
Vision science encompasses all studies of vision ...
. The crater
Ricco on the
Moon
The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...
is named after him, as is the asteroid
18462 Ricco. Ricco was also awarded the
Janssen Medal in 1906 by the
French Academy of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
for his work in astrophysics. He was also awarded the
Prix Jules Janssen of the
Société astronomique de France (French Astronomical Society) in 1914.
He died in
Rome
Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...
, Italy.
References
On the History of the Palermo Astronomical Observatory
Riccò Annibalebiography.
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{{DEFAULTSORT:Ricco, Annibale
1844 births
1919 deaths
Italian geophysicists
Polytechnic University of Milan alumni
19th-century Italian astronomers
20th-century Italian astronomers
People from Milan