{{Short description|Mathematician and astronomer (1625–1712)}} {{EngvarB|date=July 2017}} {{Use dmy dates|date=July 2017}} {{Infobox scientist | name = Giovanni Domenico Cassini | image = Giovanni Domenico Cassini, Museo di Palazzo Poggi.jpg | caption = Portrait of Cassini, 17th century | birth_date = {{birth date|df=yes|1625|6|8}} | birth_place = [[Perinaldo]], [[County of Nice]] | death_date = {{death date and age|df=yes|1712|9|14|1625|6|8}} | death_place = Paris, France | field = [[Mathematics]]<br> [[astrology]]<br> [[astronomy]]<br> [[engineering]] | work_institution = [[University of Bologna]] | alma_mater = The Jesuit College at Genoa | doctoral_advisor = | doctoral_students = | known_for = [[Cassini Division]]<br>[[Cassini identity]]<br>[[Cassini's laws]]<br>[[Cassini oval]]<br>First to observe the division in the rings of Saturn | prizes = | footnotes = | children = [[Jacques Cassini]] | signature = Giovanni Domenico Cassini signature.png }}
'''Giovanni Domenico Cassini'''{{efn|His name may also be spelled '''Giovan Domenico Cassini''' or '''Gian Domenico Cassini'''; also known as '''Jean-Dominique Cassini'''.}} (8-11 June 1625 – 14 September 1712) was an Italian-French<ref>Joseph A. Angelo, Encyclopedia of Space and Astronomy, Infobase Publishing – 2014, page 114</ref> [[mathematician]], [[astronomer]], [[astrologer]] and [[engineer]]. Cassini was born in [[Perinaldo]],<ref name="messier.seds.org">{{cite web|title=Giovanni Domenico Cassini (June 8, 1625 – September 14, 1712)|url=http://messier.seds.org/xtra/Bios/cassini.html|work=Messier Seds.org|access-date=31 October 2012}}</ref><ref>{{cite web|title=Giovanni Domenico Cassini: The rings and moons of Saturn|url=http://www.surveyor.in-berlin.de/himmel/Bios/Cassini-e.html|work=Surveyor in Berlin.de|access-date=31 October 2012|archive-date=24 June 2013|archive-url=https://web.archive.org/web/20130624233219/http://www.surveyor.in-berlin.de/himmel/Bios/Cassini-e.html|url-status=dead}}</ref> near [[Imperia]], at that time in the [[County of Nice]], part of the [[Savoyard state]].<ref>Augusto De Ferrari (1978), [http://www.treccani.it/enciclopedia/giovan-domenico-cassini_(Dizionario-Biografico)/ "Cassini, Giovan Domenico"] ''Dizionario Biografico degli Italiani'' '''21''' (Rome: Istituto dell'Enciclopedia Italiana).</ref><ref>{{cite book|last=Gandolfo, Andrea |title=La provincia di Imperia: storia, arti, tradizioni|publisher=Blue Edizioni, 2005}}</ref> He discovered four satellites of [[Saturn (planet)|Saturn]] and noted the division of its rings, later named the [[Cassini Division]]. Cassini was also the first of his family to begin work on the project of creating a [[topographic map]] of France. In addition, he also created the first scientific map of the [[Moon]].<ref>{{Cite web |title=c11371-07 |url=https://imagesonline.bl.uk/asset/148404/ |access-date=2024-10-24 |website=British Library Images |language=en-GB}}</ref>
The [[Cassini–Huygens|''Cassini'' space probe]], launched in 1997, was named after him and became the fourth to visit Saturn and the first to orbit it.
==Life== ===Time in Italy===
Cassini was the son of Jacopo Cassini, a Tuscan, and Giulia Crovesi. In 1648 Cassini accepted a position at the observatory at [[:it:Panzano, Castelfranco Emilia|Panzano (Castelfranco Emilia)]], near [[Bologna]], to work with Marquis [[Cornelio Malvasia]], a rich amateur astronomer, initiating the first part of his career.<ref name="Cassini">{{cite book|last=Cassini, Gian Domenico (Jean-Dominique) (Cassini I) |title=Complete Dictionary of Scientific Biography|publisher=Detroit: Charles Scribner's Sons, 2008 |pages=100–104. retrieved 30 May 2013}}</ref> During his time at the [[Panzano Observatory]], Cassini was able to complete his education under the scientists [[Giovanni Battista Riccioli]] and [[Francesco Maria Grimaldi]]. In 1650 the senate of Bologna appointed him as the principal chair of astronomy at the [[University of Bologna]].<ref name="Cassini"/>
While in his position in Bologna, he observed and wrote a book on the [[C/1652 Y1|comet of 1652]]. He was also employed by the senate of Bologna as a [[Hydraulic engineering|hydraulic engineer]], and appointed by [[Pope Alexander VII]] inspector of fortifications in 1657. He was subsequently director of waterways in the papal states.<ref name="EB1911">{{EB1911|inline=y|wstitle=Cassini|display=Cassini s.v. Giovanni Domenico Cassini|volume=5|page=459|first=Agnes Mary|last=Clerke|author-link=Agnes Mary Clerke}}</ref>
[[File:Osservazione del solstizio 21.06.12, fi, 20.JPG|thumb|left|The pinhole-projected image of the Sun on the floor at [[Florence Cathedral]]. Cassini measured a similar image over a year at San Petronio Basilica to try to prove the Earth orbited the Sun.]] In San Petronio, Bologna, Cassini convinced church officials to create an improved sundial [[San Petronio Basilica#Cassini.27s Sundial|meridian line at the San Petronio Basilica]], moving the [[pinhole gnomon]] that projected the Sun's image up into the church's vaults 66.8 meters (219 ft) away from the meridian inscribed in the floor. The much larger image of the Sun's disk projected by the [[camera obscura]] effect allowed him to measure the change in diameter of the Sun's disk over the year as the Earth moved toward and then away from the Sun. He concluded the changes in size he measured were consistent with [[Johannes Kepler]]'s 1609 heliocentric theory, where the Earth was moving around the Sun in an elliptical orbit instead of the [[geocentric model#Ptolemaic system|Ptolemaic system]] where the Sun orbited the Earth in an eccentric orbit.<ref>{{cite news |url=https://www.nytimes.com/1999/10/19/science/how-the-church-aided-heretical-astronomy.html|first=William J. |last=Broad |title=How the Church Aided 'Heretical' Astronomy |date=19 October 1999 |newspaper=New York Times}}</ref>
Cassini remained in Bologna working until [[Jean-Baptiste Colbert|Colbert]] recruited him to come to Paris to help set up the [[Paris Observatory]]. Cassini departed from Bologna on 25 February 1669.<ref name="Cassini"/>
===Moving to France=== [[File:Paris Observatory XVIII century.png|thumb|right|250px|An engraving of the [[Paris Observatory]] during Cassini's time. The tower on the right is the "''Marly Tower''", a dismantled part of the [[Machine de Marly]], moved there by Cassini for mounting long focus and [[aerial telescope]]s.]]
Cassini's determinations of the rotational periods of Jupiter and Mars in 1665–1667 enhanced his fame, and in 1669, with the reluctant assent of the Pope, he moved to France and through a grant from [[Louis XIV]], the "Sun King" of France, helped to set up the [[Paris Observatory]], which opened in 1671;<ref name="EB1911"/> he would remain the director of the observatory for the rest of his career until his death in 1712. For the remaining 41 years of his life Cassini served as [[astrology and astronomy|astronomer/astrologer]] to Louis; serving the expected dual role yet focusing the overwhelming majority of his time on astronomy rather than the astrology he had studied so much in his youth. Cassini thoroughly adopted his new country, to the extent that he became interchangeably known as Jean-Dominique Cassini, although that is also the name of his great-grandson, [[Dominique, comte de Cassini]].
During this time, Cassini's method of determining longitude was used to measure the size of France accurately for the first time. The country turned out to be considerably smaller than expected, and the king quipped that Cassini had taken more of his kingdom from him than he had won in all his wars.
On 14 July 1673 Cassini obtained the benefits of French citizenship. In 1674 he married Geneviève de Laistre, the daughter of the lieutenant general of the comté of Clermont. "From this marriage Cassini had two sons; the younger, [[Jacques Cassini]], succeeded him as astronomer and [[geodesy|geodesist]] under the name of Cassini II."<ref name="Cassini"/>
In 1711, Cassini went blind, and he died on 14 September 1712 in Paris at the age of 87.<ref name="messier.seds.org"/>
==Astronomer== [[File:Giovanni Domenico Cassini, Biblioteca Aprosiana.jpg|thumb|Portrait of Cassini (no later than 1667)]] Cassini observed and published surface markings on [[Mars]] (earlier seen by [[Christiaan Huygens]] but not published), determined the rotation periods of Mars and [[Jupiter]], and discovered four satellites of [[Saturn]]: [[Iapetus (moon)|Iapetus]] and [[Rhea (moon)|Rhea]] in 1671 and 1672, and [[Tethys (moon)|Tethys]] and [[Dione (moon)|Dione]] (1684).<ref>{{cite journal|last=Van Helden|first=Albert|title=The beginnings, from Lipperhey to Huygens and Cassini|journal=Experimental Astronomy|volume=25|issue=1–3|doi=10.1007/s10686-009-9160-y|year=2009|page=3|bibcode=2009ExA....25....3V|doi-access=free}}</ref> Cassini was the first to observe these four [[natural satellite|moon]]s, which he called ''[[Sidera Lodoicea]]'' (the stars of Louis), including [[Iapetus (moon)|Iapetus]], whose anomalous variations in brightness he correctly ascribed as being due to the presence of dark material on one hemisphere (now called [[Cassini Regio]] in his honour). In addition, he discovered the [[Cassini Division]] in the rings of Saturn in 1675.<ref name="Cassini"/> He shares credit with [[Robert Hooke]] for the discovery of the [[Great Red Spot]] on Jupiter (ca. 1665). Around 1690, Cassini was the first to observe [[differential rotation]] within Jupiter's [[celestial body atmosphere|atmosphere]].
In 1672, he sent his colleague [[Jean Richer]] to [[Cayenne]], [[French Guiana]], while he himself stayed in Paris. The two made simultaneous observations of Mars and, by computing the [[parallax]], determined its distance from Earth. This allowed for the first time an estimation of the dimensions of the [[Solar System]]: since the relative ratios of various Sun-planet distances were already known from geometry, only a single absolute interplanetary distance was needed to calculate all of the distances.
[[File:Carte de la Lune de Giovanni Domenico Cassini.jpg|thumb|Cassini's map of the Moon]]
In 1677, the English philosopher [[John Locke]] visited Cassini in Paris. He writes, "At the Observatory, we saw the Moon in a twenty-two foot glass, and Jupiter, with his satellites, in the same. The most remote was on the east, and the other three on the west. We also saw Saturn and his rings, in a twelve-foot glass, and one of his satellites."<ref>{{cite book |last1=Locke |first1=John |title=The life and letters of John Locke : with extracts from his journals and common-place books |date=1864 |publisher=Bell & Daldy |location=London |page=73 |url=https://books.google.com/books?id=UHpmAAAAMAAJ&q=The+Life+and+Letters+of+John+Locke:+With+Extracts+from+His+Journals+and}}</ref>
Cassini initially held the Earth to be the centre of the Solar System, though later observations compelled him to accept the model of the Solar System proposed by [[Nicolaus Copernicus]], and eventually that of [[Tycho_Brahe#The_Tychonic_cosmological_model|Tycho Brahe]]. "In 1659 he presented a model of the planetary system that was in accord with the hypothesis of Nicolaus Copernicus. In 1661 he developed a method, inspired by Kepler's work, of mapping successive phases of [[solar eclipse]]s; and in 1662 he published new tables of the sun, based on his observations at San Petronio."<ref name="Cassini"/> Cassini also rejected Newton's [[Newton's law of universal gravitation|theory of gravity]], after measurements he conducted which wrongly suggested that the Earth was elongated at its poles. More than forty years of controversy about the subject were closed in favour of Newton's theory after the measurements of the [[French Geodesic Mission]] (1736 to 1744) and the Lapponian expedition in 1737 led by [[Pierre Louis Moreau de Maupertuis]].
Cassini was also the first to make successful measurements of [[History of longitude|longitude]] by the method suggested by [[Galileo Galilei|Galileo]], using eclipses of the [[Galilean satellites]] as a clock.
In 1683, Cassini presented the correct explanation of the phenomenon of [[zodiacal light]].<ref name="EB1911"/> Zodiacal light is a faint glow that extends away from the Sun in the ecliptic plane of the sky, caused by dusty objects in interplanetary space.
Cassini is also credited with introducing [[Indian Astronomy]] to Europe. In 1688, the French envoy to [[Siam]] (Thailand), [[Simon de la Loubère]], returned to Paris with an obscure manuscript relating to the astronomical traditions of that country, along with a French translation. The Siamese Manuscript, as it is now called, somehow fell into Cassini's hands. He was intrigued enough by it to spend considerable time and effort deciphering its cryptic contents,{{citation needed|date=April 2020}} also determining on the way that the document originated in [[India]].<ref>{{Cite journal |last=Burgess |first=James |title=Notes on Hindu Astronomy and the History of Our Knowledge of It |url=https://books.google.com/books?id=00KWxLxhPN4C&pg=PA722 |journal=Journal of the Royal Asiatic Society of Great Britain & Ireland |year=1893 |pages=722–723}}</ref> His explication of the manuscript appeared in La Loubère's book on the Kingdom of Siam in 1691.<ref name=Loubère>{{cite book|last1=de La Loubère|first1=Simon|translator=A.P.|title=A New Historical Relation of the Kingdom of Siam|date=1693| url=https://archive.org/details/bub_gb_RvpBAQAAMAAJ/page/n83/mode/2up|access-date=16 October 2017|language=en |pages=64–65}}</ref>{{primary source inline|date=April 2020}}
==Astrologer== Attracted to the heavens in his youth, his first interest was in [[astrology]]. While young he read widely on the subject, and soon was very knowledgeable about it; this extensive knowledge of astrology led to his first appointment as an astronomer. Later in life he focused almost exclusively on [[astronomy]] and all but denounced astrology as he became increasingly involved in the [[Scientific Revolution]].
In 1645 the Marquis [[Cornelio Malvasia]], a senator of [[Bologna]] with a great interest in astrology, invited Cassini to Bologna and offered him a position in the Panzano Observatory, which he was constructing at that time. Most of their time was spent calculating newer, better, and more accurate [[ephemeris|ephemerides]] for astrological purposes using the rapidly advancing astronomical methods and tools of the day.
==Engineering== [[File:1744 carte Cassini triangulée seule.jpg|thumb|Cassini's map of France, 1744]] In 1653, Cassini, wishing to employ the use of a meridian line, sketched a plan for a new and larger meridian line but one that would be difficult to build. His calculations were precise; the construction succeeded perfectly; and its success gave Cassini a brilliant reputation for working with engineering and structural works.<ref name="Cassini"/>
Cassini was employed by [[Pope Clement IX]] in regard to [[fortification]]s, [[river management]], and flooding of the [[Po River]]. "Cassini composed several memoirs on the flooding of the [[Po River]] and on the means of avoiding it; moreover, he also carried out experiments in applied hydraulics."<ref name="Cassini"/> In 1663 he was named superintendent of [[fortification]]s and in 1665 inspector for [[Perugia]].<ref name="Cassini"/> The Pope asked Cassini to take [[Holy Orders]] to work with him permanently but Cassini turned him down because he wanted to work on astronomy full-time.
In the 1670s, Cassini began work on a project to create a [[topography|topographic]] map of France, using [[Gemma Frisius]]'s technique of [[triangulation]]. The project was continued by his son [[Jacques Cassini]] and eventually finished by his grandson [[César-François Cassini de Thury]] and published as the ''Carte de Cassini'' in 1789<ref>{{cite encyclopedia|url=https://www.britannica.com/biography/Cesar-Francois-Cassini-de-Thury |title=Cesar-Francois Cassini de Thury (French surveyor) |encyclopedia=Encyclopædia Britannica |access-date=5 November 2013}}</ref> or 1793.<ref>{{cite web|url=http://www.madehow.com/Volume-4/Topographic-Map.html |title=How topographic map is made – making, history, used, History, Map Scales, Symbols, and Colors, The Manufacturing Process of topographic map, Quality Control, The Future |publisher=Madehow.com |date=2 September 2013 |access-date=5 November 2013}}</ref> It was the [[history of cartography|first topographic map of an entire country]].
==Works== [[File:Giovanni Domenico Cassini – Raccolta di varie scritture, e notitie concernenti, 1682 - BEIC 1285500.jpg|thumb|''Raccolta di varie scritture'' (1682)]]
* {{Cite book|title=Specimen observationum Bononiensium|volume=|publisher=eredi Evangelista Dozza (1.)|location=Bologna|year=1656|language=la|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=87221}} * {{Cite book|title=Martis circa axem proprium revolubilis observationes Bononiae habitae|volume=|publisher=eredi Evangelista Dozza (1.)|location=Bologna|year=1666|language=la|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=1252522}} * {{Cite book|title=Spina celeste meteora osservata in Bologna il mese di marzo 1668|volume=|publisher=Emilio Maria Manolessi & fratelli|location=Bologna|year=1668|language=it|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=1251926}} * {{Cite book|title=Observations astronomiques faites en divers endroits du royaume, pendant l'année 1672|volume=|publisher=|location=|year=|language=fr|url=https://gallica.bnf.fr/ark:/12148/bpt6k15109171}} * {{Cite book|title=Abregé des observations et des reflections sur la comete qui a paru au mois de Decembre 1680, et aux mois de Ianvier, Fevrier et Mars de cette annee 1681 |volume=|publisher=Estienne Michallet|location=Paris|year=1681|language=fr|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=1251645}} *{{cite book|publisher= [s.n.]|last= Cassini|first= Giovanni Domenico|title= Raccolta di varie scritture, e notitie concernenti l'interesse della remotione del Reno dalle Valli fatta in Bologna l'anno 1682 |place=(In Bologna)|year= 1682|url= https://gutenberg.beic.it/webclient/DeliveryManager?pid=1285500}} * {{Cite book|title=Elemens de l'astronomie|volume=|publisher=Imprimerie Royale|location=Paris|year=1684|language=fr|url=https://gallica.bnf.fr/ark:/12148/bpt6k1510919v}} * {{Cite book|title=Découverte de la lumiere celeste qui paroist dans le zodiaque|volume=|publisher=Imprimerie Royale|location=Paris|year=1685|language=fr|url=https://doi.org/10.3931/e-rara-7552}} * {{Cite book|title=Régles de l'astronomie indienne pour calculer les mouvemens du soleil et de la lune|volume=|publisher=Sébastien Mabre-Cramoisy, veuve|location=Paris|year=1689|language=fr|url=https://doi.org/10.3931/e-rara-7550 }} * {{Cite book|title=De l'origine et du progres de l'astronomie et de son usage dans la geographie et dans la navigation|volume=1|publisher=Imprimerie Royale|location=Paris|year=1693|language=fr|url=https://doi.org/10.3931/e-rara-7547 }} * {{Cite book|title=Hypotheses et les tables des satellites de Jupiter, reformeés sur de nouvelles observations|volume=|publisher=Jean Anisson|location=Paris|year=1693|language=fr|url=https://doi.org/10.3931/e-rara-9309 }} * {{Cite book|title=Meridiana del tempio di S. Petronio tirata e preparata per le osservazioni astronomiche l'anno 1655|volume=|publisher=eredi Vittorio Benacci |location=Bologna|year=1695|language=it|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=1251458}} * {{Cite book|title=Description et usage du planisphere céleste|volume=|publisher=|location=|year=|language=fr|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=1449900}} *[https://bibnum.obspm.fr/ark:/11287/29mJR Cassini's works] digitalized and available on the digital library of [[Paris Observatory]]
==See also== {{Div col|colwidth=28em}} *[[24101 Cassini]], an [[asteroid]] *[[Aerial telescope]] – large telescopes used by Cassini *[[Cassini (lunar crater)]] *[[Cassini (Martian crater)]] *[[Cassini Division]] in [[Saturn]]'s rings *[[Cassini oval]] *[[Cassini Regio]], dark area on [[Iapetus (moon)|Iapetus]] *[[Cassini–Huygens|''Cassini–Huygens'' Mission]] to [[Saturn]] *[[Cassini and Catalan identities|Cassini's identity]] for [[Fibonacci number]]s *[[Cassini's laws]] *[[History of the metre]] *[[Neith (hypothetical moon)]] *[[Seconds pendulum]] {{Div col end}}
==References== {{Notelist}} {{Reflist}}
==Further reading== *[[Dominique, comte de Cassini]], [https://bibnum.obspm.fr/ark:/11287/41ccp Giovanni Dominico Cassini biography] {{Webarchive|url=https://web.archive.org/web/20180427184733/https://bibnum.obspm.fr/ark:/11287/41ccp |date=27 April 2018 }} *{{cite journal |title= On Cassini's laws |author= Barkin, Iu. V. |year= 1978 |journal= Astronomicheskii Zhurnal |volume= 55 |pages= 113–122 |bibcode= 1978SvA....22...64B}} *{{cite journal |title= The Cassini Family and the Paris Observatory |author= Connor, Elizabeth |year= 1947 |journal= Astronomical Society of the Pacific Leaflets |volume= 5 |issue= 218 |pages= 146–153 |bibcode= 1947ASPL....5..146C}} *Cassini, Anna, ''Gio. Domenico Cassini. Uno scienziato del Seicento'', Comune di Perinaldo, 1994. (Italian) *Cuesta, JAF, ''Cassini y el origen de la astronomía experimental'', in La cosmovisión de los grandes creadores de la ciencia moderna: convicciones éticas, políticas, filosóficas o religiosas de los protagonistas de la renovación del saber en los siglos XVI y XVII / coord. por Juan Arana Cañedo-Argüelles, 2023. (Spanish) *Giordano Berti (a cura di), ''G.D. Cassini e le origini dell'astronomia moderna'', catalogo della mostra svoltasi a Perinaldo -Im-, Palazzo Comunale, 31 agosto – 2 novembre 1997. (Italian) *Giordano Berti e Giovanni Paltrinieri (a cura di), ''Gian Domenico Cassini. La Meridiana del Tempio di S. Petronio in Bologna'', Arnaldo Forni Editore, S. Giovanni in Persiceto, 2000. (Italian) *{{cite web|url=http://www.treccani.it/enciclopedia/giovan-domenico-cassini_(Dizionario-Biografico)/|work=Dizionario Biografico degli Italiani|publisher=Enciclopedia Italiana|access-date=2 December 2016|author=De Ferrari, Augusto|language=it|title=Cassini, Giovan Domenico|year=1978}} *Narayanan, Anil, ''History of Indian Astronomy: The Siamese Manuscript'', Lulu Publishing, 2019.
==External links== {{commons}} {{wikiquote}} {{EB1911 poster|Saturn (planet)}} * {{CE1913|wstitle=Giovanni Domenico Cassini}} *{{MacTutor|id=Cassini}} *[https://amshistorica.unibo.it/giovannicassini Giovanni Domenico Cassini – complete digitization of 14 volumes belonging to the Old Fund's Department of Astronomy, University of Bologna, held to mark the celebrations of the Cassini in 2005 ''(website in Italian)''] *[https://www.space.com/18902-giovanni-cassini.html Giovanni Cassini Biography] -Space.com *[http://www.esa.int/Our_Activities/Space_Science/Jean-Dominique_Cassini_Astrology_to_astronomy esa.int — Jean-Dominique Cassini: Astrology to astronomy] -ESA *[http://www.geoastro.de/EarthShape/index.html Geoastro.de Earth shape] *[https://bibnum.obspm.fr/exhibits/show/cassini Virtual exhibition on Paris Observatory digital library]
{{Cassinimission|state=collapsed}} {{Portal bar|Biography|Italy|Mathematics|Astronomy|Stars|Outer space|Solar System|Science}} {{Authority control}}
{{DEFAULTSORT:Cassini, Giovanni Domenico}} [[Category:Giovanni Domenico Cassini| ]] [[Category:Discoverers of moons]] [[Category:French fellows of the Royal Society]] [[Category:Italian astrologers]] [[Category:17th-century Italian astronomers]] [[Category:Emigrants from the Savoyard state]] [[Category:Immigrants to France]] [[Category:Italian Roman Catholics]] [[Category:Members of the French Academy of Sciences]]
[[Category:Selenographers]] [[Category:1625 births]] [[Category:1712 deaths]] [[Category:17th-century astrologers]] [[Category:17th-century Italian mathematicians]] [[Category:17th-century Roman Catholics]] [[Category:18th-century astrologers]] [[Category:18th-century Italian mathematicians]] [[Category:18th-century Roman Catholics]] [[Category:Discoverers of astronomical objects]] [[Category:People from the Savoyard state]] [[Category:Italian fellows of the Royal Society]]