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44 MAY-JUNE 2014 DWARF PLANETS population. Circular orbits are much more efficient in the accre- tion process of a pla- netary mass, starting from the material available in the pro- toplanetary disk, and this is much more so the more these orbits are smaller. What me- chanism has thus fa- voured their forma- tion and/or location in the regions where we can observe them today? The simula- tions have allowed the researchers to build two main forma- tion models capable of describing the crea- tion of the inner Oort Cloud. The first is based on the ejection from the solar system D iagrams help- ful for under- standing the inner Oort Cloud. In the left one it can be noticed that ob- jects less than 150 AU from the Sun have random ar- guments of peri- helion ( ω ), while for those at great- er distances they tend to be distrib- uted around 0° (or 360°). The one below represents the libration of ω for 2012 VP 113 pre- dicted over a pe- riod of 2 billion years. There is co- herence with the potential presence of a super-Earth at 210 AU. [C. Trujillo and S. Sheppard] from the Sun. Sedna and 2012 VP 113 are therefore the first representatives of the newly discovered population of icy bodies, whose total number (including smaller co- metary nuclei) should exceed that of all other populations of small bodies of the solar system. Trujillo and Sheppard estimate that in the inner part of the Oort Cloud could exist from 400 to 1700 dwarf planets with a diameter greater than 1000 km, this according to the size distribution models al- ready applied to the main asteroid belt and the Edgeworth-Kuiper belt. The numerical simulations suggest that the total mass of the newly found population could be closer to 1/80 of the Earth’s mass (for comparison, all the objects in the Edgeworth-Kuiper belt amount to 1/100 of the Earth’s mass). From the highly elongated shape of Sedna’s and 2012 VP 113 ’s orbits, it is possible to con- strue that these two dwarf planets cannot have formed by gathering material on their trajectories, and this applies also to a doz- en of other candidate objects currently wait- ing to be classified as belonging to the new