Azerbaijan National Academy of Science

A dwarf planet nicknamed the Goblin has been discovered well beyond Pluto, further redefining our solar system.

A round frozen world just 300 kilometres across, the Goblin was spotted by astronomers in 2015 around Halloween, thus its spooky name. But it wasn't publicly unveiled until now following further observations with ground telescopes.

One of the astronomers who made the discovery, Scott Sheppard of the Carnegie Institution for Science, said the Goblin was on the small end for a dwarf planet. It is officially known as 2015 TG387 by the International Astronomical Union's Minor Planet Centre.

This is the third dwarf planet recently found to be orbiting on the frigid fringes of our solar system.

Goblin's orbit is extremely elongated — so stretched out, in fact, that it takes 40,000 years for it to circle the sun.

At its most distant, the Goblin is 2,300 times further from the sun than Earth. That's 2,300 astronomical units (AU). One AU is the distance from Earth to the sun, or roughly 150 million kilometres.

At its closest, the Goblin is 65 times farther from the sun than Earth, or 65 AU. Pluto, by comparison, is approximately between 30 and 50 AU.

Dr Sheppard, along with Northern Arizona University's Chad Trujillo and the University of Hawaii's David Tholen, spotted the Goblin in October 2015 when it was relatively nearby — around 80 AU.

www.abc.net.au