‘Dwarf planet’ discovered in distant Solar System

A rare “dwarf planet” 18 times smaller than Earth,
has been discovered in the distant Solar System on
an eccentric orbit far beyond Neptune, astronomers
said Tuesday.
Dubbed RR245, the icy world is currently about 9.7
billion kilometres (six billion miles) from the Sun —
65 times further than Earth, said astronomer Jean-
Marc Petit of France’s CNRS research institute.
“But its orbit is very elliptical, and it will be 19
billion km at its furthest point” from our star,” he
told AFP.
At the closest approach on its 700-year orbit, the
planet will pass the Sun at a distance of some five
billion km.
Dwarf planets fall into a six-year-old category of
celestial bodies.
They are smaller than ordinary planets and orbit
the Sun at a much greater distance, travelling in a
zone littered with other objects like asteroids.
There are thought to be dozens of them in our Solar
System, but only a handful have been identified so
far.
They include Eris and Ceres, as well as Pluto —
which was downgraded from a full planet to a
dwarf planet in a 2006 decision that remains
contested to this day.
Most dwarf planets are small and dark, said team
member Michele Bannister of the University of
Victoria in Canada.
“It is really exciting to find one which is big and
bright enough for us to study,” she said in a
statement issued by the CNRS.
RR245 was first spotted in February this year, in
images taken in September 2015 by Outer Solar
System Origin Survey (OSSOS), an international
project to scope out distant worlds.
Its diameter has been estimated at about 700 km,
compared to Earth’s more than 12,700 km.
The discoverers of RR245 have the right to propose
a name for their find.
New planetary monickers have to be approved by
nomenclature panel in the International
Astronomical Union (IAU).