- An ion (/ˈaɪ.ɒn, -ən/) is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons.
- Star Tales - Antlia (ianridpath.com)
Antlia is one of the constellations of the southern sky introduced by the French astronomer Nicolas Louis de Lacaille on his map of 1756. He said in the accompanying description that it symbolized experimental physics. Lacaille originally called the constellation la Machine Pneumatique but Latinized this to Antlia Pneumatica on the second edition of the map published in 1763. Following a suggestion by John Herschel, the English astronomer Francis Baily shortened its name to just Antlia in his British Association Catalogue of 1845, and it has been known as that ever since.