Sixth dwarf planet found

Sixth dwarf planet found

An astronomer who's already found more than 20 moons has made perhaps his biggest find yet - a new dwarf planet.

2015 RR245, as it's currently known, was first spotted in February 2016 by Canadian stargazer J.J. Kavelaars, while looking at images taken by a telescope sitting on Mauna Kea, a dormant volcano in Hawaii, in September 2015.

"It was really remarkable to see how bright this object was," said Michele Bannister, astronomer at the University of Victoria, Canada. "It's far brighter than the objects we normally find."

It's estimated to be about 700km in diameter, give or take, and takes about 700 years to orbit the sun. Its journey is elliptical, coming in almost as close as fellow dwarf Pluto and swinging out more than twice as far as Neptune.

Sixth dwarf planet found

2015 RR245 isn't going to get a better name anytime soon, so don't bother suggesting astronomers name it after the latest Pokémon you've caught. The International Astronomical Union only decides on names once an object's orbit has been tracked for a number of years, and its size and composition confirmed.

"It's either small and shiny, or large and dull," says Dr Bannister.

It's currently inbound, and expected to make its closest approach to the sun in 2096.

There are currently five confirmed dwarf planets - Ceres, Sedna, Pluto, Haumea, Makemake and Eris - but astronomers think there are hundreds more waiting to be found.

There is also growing gravitational evidence of a ninth full-size planet well beyond the orbits of Neptune and Pluto.