The new planet, named RR245, was discovered in 2015 using the Canada-France-Hawaii Telescope, located in Maunakea, Hawaii, as part of the ongoing Outer Solar System Origins Survey (OSSOS). RR245 is roughly 435 miles in diameter and lies some 7.4 billion miles from the sun. The Earth’s farthest point from the sun is 94.5 million miles.
The dwarf planet was first spotted by scientists in February of this year, during a review of OSSOS data from September 2015. RR245 has been in its current orbit at least for the last 100 million years, and will emerge from its highly elliptical path to come as close as 3 billion miles to the sun in 2096, its closest approach.
Michele Bannister from the University of Victoria in British Columbia, a postdoctoral fellow with OSSOS said, "The icy worlds beyond Neptune trace how the giant planets formed and then moved out from the Sun. They let us piece together the history of our Solar System. But almost all of these icy worlds are painfully small and faint. It's really exciting to find one that's large and bright enough that we can study it in detail."
The International Astronomical Union defines a dwarf planet as body that is nearly round, orbits the sun and has enough mass to clear the sun’s orbit. There may be hundreds of dwarf planets in the Kuiper Belt, as well as in the area between Mars and Jupiter, but, excluding RR245, astronomers have only been able to find five: Haumea, Pluto, Ceres, Makemake and Eris.
Researchers said in a statement, "Worlds that journey far from the Sun have exotic geology with landscapes made of many different frozen materials, as the recent flyby of Pluto by the New Horizons spacecraft showed…RR245 is one of the few dwarf planets that has survived to the present day — along with Pluto and Eris, the largest known dwarf planets. RR245 now circles the Sun among the remnant population of tens of thousands of much smaller trans-Neptunian worlds, most of which orbit's is unseen."