The unusual orbit of a possible dwarf planet, known as 2017 OF201, makes it less likely that our solar system contains a hidden ninth “Planet X” The orbits of a potential dwarf planet called 2017 OF201 and the dwarf planet Sedna Tony Dunn This far-flung orbit may be the result of an encounter with a giant planet, which ejected the candidate dwarf planet out of the solar system, say the researchers.