How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between five and 18, plus hundreds of potentially undiscovered ones, depending on ...

In 2006, and after much debate, the International Astronomical Union came up with a new definition for a planet. And for the first time, the term "dwarf planet" was used. Dwarf Planets ...

Makemake is the third-largest known dwarf planet in our solar system, after Pluto and Eris, with a diameter of 888 miles across. It takes about 309 years to orbit the sun.

Astronomers pointed out that the seven planets orbit TRAPPIST-1, a dwarf star that is much younger than our sun and should burn for an additional 10 trillion years — more than 700 times longer ...

New dwarf planet could dash Planet X hypothesis The new object could also challenge the hypothesis that there's a "Planet X" or "Planet Nine" beyond Pluto, with gravity affecting dwarf planets and ...