Pickering's Planets is a group of hypothetical planets proposed by William Henry Pickering from 1909 to 1938. Over about 7 to nearly 11 of these planets were proposed, but neither of which were ever confirmed.[1]
History[]
While most astronomers over the years proposed that 1, 2, or 3 planets exist's beyond Neptune's orbit, W. H. Pickering postulated over about 7 planet's sitting beyond Neptune, which each of their orbital parameters and masses being specified by him between 1909 to 1938. These planets were named O, P, Q, R, S, T, and U. By 1919 to 1931, 4 additional planets were included within the hypothesis, these being named O2, O3, P2, and P3, respectively.[2]
Over time, a few of the proposed planets were left out due to many reasons. Planet T, originally proposed in 1931, was left out due to its uncertainty. Planets S and U were also left out, as a result of their derivations being carried out after the discovery of Pluto. The 3 planet P's, and Planets Q and R, were later on left out from the hypothesis, due to their extreme distances and year lengths in contrast to the 3 planet O's postulated by Pickering.[3]
Planet O3 would then be left out, as a result of its orbital distance and period being placed at a similar distance to Neptune. This now leaves to only 2 planets, O1 and O2. Similar to what happened with Brahma, another hypothetical planet, it has been noted that the orbital values for both O1 and O2 appear similar to that of Pluto, albeit with some slight differences in their orbital inclinations and distances, with O1's inclination being close to Pluto's inclination at the time.[4]
Since then, neither of the postulated planets by Pickering have never been confirmed, and most likely do not exist.
Parameters[]
While it is unclear of what types of planets were they, as Pickering never specified of what they were, their planetary types can be speculated from their specified masses.
Planet U has a mass of over 0.045 Earth's. This mass is a lot less than that of Mercury, but higher than that of Pluto. So, it can be thought of that U is an icy terrestrial. Curiously, its orbital distance is 5.79 AU,[5] which puts it in an orbit between Jupiter and Saturn.
O3 is specified to have a mass of over 0.5 Earth's. This is quite close to the mass of Mercury, and likely means that it's another icy terrestrial. However, its orbital distance is over 30.1 AU, which would place it very close to Neptune.[6]
Planets O1 and O2 are specified to have masses of over 2.0 Earth masses,[7] meaning that they can be considered as Super-Earth's, a type of planet with a mass higher than Earth. O1 sits over about 51.9 AU away from the Sun, while O2 sits over about 55.1 AU away.
Planet S's mass is stated to be 5.3 Earth masses, which would also make it a Super-Earth. S sits more closer to the Sun compared to O1 and O2, as it is stated to sit at 48.3 AU away.[8]
P2's mass is stated to be 20 Earth masses, which would likely make it an ice giant similar to Uranus or Neptune, more or less a "Super-Neptune".[9] P2 is thought to sit over about 67.7 AU away from the Sun, which is a lot further compared to the distances of the 2 planet O's.[10]
P3 is thought to be 49.6 Earth masses. This likely means that it is also a "Super-Neptune". The planet also sits much further away, at over 75.5 AU.
Planet R, in contrast to the other planet's, is specified to have a mass of over 10,000 Earth masses,[11] or 31.455 Jupiter masses. This puts within the boundary of a Y-type brown dwarf, which usually have masses between 3 to 29 Jupiter masses.[12] The planet is said to sit at over 6,250 AU away, which is the farthest compared to the rest of the planets.[13]
Q, similar to R, has a very high mass of over 20,000 Earth's,[14] or 62.911 Jupiter masses. This puts Q well above a Y-type brown dwarf, and likely makes it into an L-type brown dwarf.[15] Unlike R, Q is stated to sit over 875 AU away from the Sun.
The masses for both Planets P1 and T have never been specified, so it's hard to tell of what they're supposed to be. P1 is stated to sit 123 AU away, while T is stated to sit at a closer distance, at about 32.8 AU.[16]
References[]
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ W. H. Pickering's Planetary Predictions and the Discovery of Pluto
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Super-Neptune Planet Found
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Prediction of Pluto by V. P. Ketakar
- ↑ Impact of a new H/He equation of state on the evolution of massive brown dwarfs. New determination of the hydrogen burning limit
- ↑ Prediction of Pluto by V. P. Ketakar
| Hypothetical Bodies, Hypothetical Objects, Hypothetical Regions and Hypotheses | ||
|---|---|---|
| Hypothetical planets | Inner Solar System | Enyo and Bellona • Vulcan • Counter-Earth • Nibiru • Theia • Phaeton • Planet V • Krypton |
| Outer Solar System | Fifth Giant • Uranus Impactor • Triton’s Binary Partner • Haumea Impactor • Quaoar Impactor • Brahma • Vishnu • Oceanus • Hades • Planet Nine • Planet Ten • Rodney's Planet • Planet X • Pickering's Planets • Trans-Plutonian planet • Tyche • Oort cloud planet | |
| Hypothetical Moons | Inner Solar System | Disproven Moons of Mercury • Neith • Petit's moon • Waltemath's moons • Bagby's Moons • Moons of Pallas • Moon of Hebe |
| Outer Solar System | Chiron • Chrysalis • Themis • Sedna I • Varuna I • Herschel's Moons | |
| Hypothetical Stellar Objects | Nemesis • Coatlicue | |
| Hypothetical Regions | Vulcanoid Belt • Hills Cloud • Oort cloud | |
| Hypotheses and Models | Himalia Crash Theory • Iapetus' Ring System • Nibiru cataclysm • Rings of the Moon | |