Alien Planet Discovered? California Astronomers Discover Unique, Huge One That Loops Around Its Star

Astronomers in California last week discovered HR 5183, an exoplanet three times the size of Jupiter that slingshots around its star on a unique path.

"The planet is unlike the planets in our solar system, but more than that, it is unlike any other exoplanets we have discovered so far," Sarah Blunt, a graduate student at the California Institute of Technology (Caltech) in Pasadena, said in a statement. Blunt was part of the team that released the report showing the discovery of HR 5183.

The study revealed that HR 5183 spends the equivalent of 45 to 100 years on the edge of its solar system, when suddenly the planet moves inward, making a highly elliptical path around its star. This makes HR 5183 unique, as exoplanets far from their stars generally have circular orbits.

The head of California Planet Search, Caltech Professor of Astronomy Andrew W. Howard, said that "the planet spends most of its time loitering in the outer part of its star's planetary system in this highly eccentric orbit, then it starts to accelerate in and does a slingshot around its star."

"We detected this slingshot motion," he added. "We saw the planet come in and now it's on its way out. This creates such a distinctive signature that we can be sure that is a real planet, even though we haven't seen a complete orbit."

HR 5183 isn't the only unique exoplanet in the universe.

Kepler-16b has been nicknamed Tatooine, after protagonist Luke Skywalker's home planet in the science fiction film franchise Star Wars. The planet circles around two stars and is 200 light years from Earth.

Kepler 22b has been called New Earth, with oceans on its surface and a rocky core. Scientists believe that the planet could possibly harbor life.

Exoplanets are planets that exist out of our solar system, with NASA saying that there are a confirmed 4,044 exoplanets.