A possible new dwarf planet has been discovered at the edge of our solar system, so far-flung that it takes around 25,000 ...

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.

As it orbits the sun once every 25,000 years, the celestial body 2017 OF201 travels beyond the Kuiper Belt into a region ...

The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

For the unversed, "Planet Nine" is a hypothetical planet which is reportedly larger than Earth that is thought to orbit ...

Researchers found the object named 2017 OF201 while searching for "Planet Nine" - a hypothetical planet thought to exist ...

There’s a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic ...

The International Astronomical Union’s Minor Planet Center, which catalogs new moons and other small bodies in the solar ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

As explained in a pre-press paper [PDF] titled “Discovery of a dwarf planet candidate in an extremely wide orbit: 2017 OF201” ...