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New dwarf planet discovered out past Neptune

Astronomers have found a new dwarf planet in the Kuiper Belt, with one of the largest orbits of any dwarf planet.

Michelle Starr Science editor
Michelle Starr is CNET's science editor, and she hopes to get you as enthralled with the wonders of the universe as she is. When she's not daydreaming about flying through space, she's daydreaming about bats.
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The orbit of RR245.

Alex Parker, OSSOS

A new dwarf planet has joined the solar system's ranks. Discovered by an international team of astronomers, the planet, named 2015 RR245 for now, is apparently just 700 kilometres in diameter, although more accurate measurements will need to be taken to gauge its exact size. And it's really far away, roughly 120 times Earth's distance from the sun, with a single orbit taking 700 years.

For comparison, Pluto has a diameter of 2,374 kilometres, and completes an orbit of the sun every 248 years.

"Finding a new dwarf planet beyond Neptune sheds light on the early phases of planet formation," said Brett Gladman of the University of British Columbia. "Since most of these icy worlds are incredibly small and faint, it's exciting to find a bright one that is easier to study, and which is on an interesting orbit."

RR245 is the first dwarf planet discovered as part of the Outer Solar System Origins Survey, and is one of potentially over 100 dwarf planets in the solar system. The next step will be refining its orbit, after which it will be given an official name.