1. the hypothetical planet was named Vulcan
In 1859, the French mathematician and astronomer Urbain Le Verrier reported that the
slow precession of Mercury's orbit around the Sun could not be completely explained by Newtonian
mechanics and perturbations by the known planets. He suggested, among possible explanations,
that another planet (or perhaps instead a series of smaller 'corpuscules') might exist in an orbit even
closer to the Sun than that of Mercury, to account for this perturbation.[101]
(Other explanations
considered included a slight oblateness of the Sun.) The success of the search for Neptune based
on its perturbations of the orbit of Uranus led astronomers to place faith in this possible explanation,
and the hypothetical planet was named Vulcan, but no such planet was ever found