Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory ...

For the dwarf planet candidate, one trip around the sun takes over 24,000 years. Its orbit challenges a proposed path for a hypothetical Planet Nine.

A team of astronomers believe they may have discovered a new dwarf planet—just like Pluto—on the edge of our solar system. The object—which orbits out beyond Neptune—has been named "2017 OF201" by the ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar ...

Researchers in the US have suggested there is a 40 percent chance a ninth planet could exist in our solar system. Planet Nine, or Planet X, which will hopefully be renamed if its existence is ever 100 ...

OF201, the object belongs to the same all-star family as Pluto: dwarf planets. Its diameter, roughly 435 miles (700 km), is ...

Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a ...

Its size is estimated to be a bit smaller than Ceres, which is the smallest of the solar system's five recognized dwarf planets and has a diameter of about 590 miles (950 km).

A possible dwarf planet, like Pluto, has been observed in our solar system, according to a preprint published in arXiv. The area of space where this planet was found was previously thought empty.