A team of astronomers has discovered a new dwarf planet in the outskirts of our solar system beyond Neptune, joining the ranks of Pluto, Ceres and other celestial objects on the smaller end of the size spectrum. The planet – tentatively named 2015 RR245 – possesses one of the largest orbits among dwarf planets, orbiting the sun just once every 700 years.
“The icy worlds beyond Neptune trace how the giant planets formed and then moved out from the sun,” said Michele Bannister of the University of Victoria in British Columbia, who participated in the research. “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 planet was first spotted in February earlier this year after the examination of images from the ongoing Outer Solar System Origins Survey (OSSOS) survey. Although its exact size is not yet known, the team believes that it falls into one of two broad categories: broad and shiny or large and dull.
Unlike most dwarf planets that were destroyed or ejected from our solar system to make way for larger planets, RR245 has survived until the present along with other large dwarf planets such as Pluto and Eris.
RR245 likely possesses unique geology composed of numerous kinds of frozen materials. However, as it has only been observed for one of the 700 years in its orbital period, further research will need to be conducted in order to reveal its exact landscapes and orbit.
“OSSOS was designed to map the orbital structure of the outer solar system to decipher its history,” said Brett Gladman, a professor from the University of British Columbia in Vancouver who participated in the research along with Bannister. “While not designed to efficiently detect dwarf planets, we’re delighted to have found one on such an interesting orbit.”
RR245 is the largest planet to be discovered by the OSSOS and will likely be the last until the mid 2020s when other larger telescopes will begin their search for celestial bodies in the outer reaches of our solar system.