Notes on an initial satellite system of Neptune

The comparison of masses and sizes of the Neptunian satellites and of Pluto and Charon to the secondaries of the planetary, Jovian, Saturnian and Uranian systems support the hypotheses, first, that an initial Neptune's satellite system may have been disrupted, second, that Triton may have been the system perturber and, third, that Pluto (or a parent body of Pluto and Charon) was initially a giant satellite of Neptune. Based on recent theoretical works on perturbed proto-planetary nebula and noting the similarity of some characteristics of Neptune and Uranus, a theoretical mean distance ratio of primeval gaseous rings around Neptune is tentatively deduced to be about 1.475, close to the value of the Uranian system. An exponential distance relation gives possible ranges of distances at which small satellites and/or ring structures could be found by Voyager 2, close to Neptune.