Jacques Cassini (Cassini II, February 18, 1677 - April 16, 1756)

Jacques Cassini (Cassini II) was born on February 18, 1677 in Paris as the son of G.D. Cassini (Cassini I). Together with his father, he was involved in the great degree measurement to improve the geographic knowledge of France. After the death of his father in 1712, he succeeded him as the director of the Paris Observatory. His astronomical activities include observations of Saturn and studies of the proper motion of stars, detecting that Arcturus (Alpha Bootis) had changed its latitude by 5' in 159 years, while neighboring Eta Bootis remained unchanged. In 1740, he published Elements of Astronomy (Cassini 1740).

He is father of César François Cassini (Cassini III). One of his assistants was Le Gentil.

Jacques Cassini died on April 16, 1756 in Thury-sous-Clermont near Beauvais, aged 79, in a carriage accident.

Jacques Cassini was honored by naming asteroid (24102) Jacquescassini, which had been discovered by C.W. Juels at Fountain Hills observatory on November 9, 1999, and provisionally designated 1999 VD9.



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