We've discovered a lot of new planets in the last few years, but this is the first one that seems to have no star to orbit.
A team of astronomers from around the world, while using the Pan-STARRS 1 telescope to search for "failed stars" known as brown dwarfs, recently spotted a gas-giant planet six times the mass of Jupiter about 80 light-years from Earth. Designated PSO J318.5-22 (and shown in the conceptual image above), the planet seems to be simply drifting through space, orbiting no star.
"We have never before seen an object free-floating in space that looks like this," team leader Dr. Michael Liu, of the Institute for Astronomy at the University of Hawaii at Manoa, said in a written statement. "It has all the characteristics of young planets found around other stars, but it is drifting out there all alone. I had often wondered if such solitary objects exist, and now we know they do."
The team originally discovered PSO J318.5-22 two years ago while searching through Pann-STARRS 1 data, and later used other telescopes in Hawaii to confirm what they were seeing. Apparent "rogue planets" have been reportedly discovered before, but in those instances no one was ever able to prove definitively whether the object in question was a planet or a brown dwarf. With PSO J318.5-22, the team has been able to confirm that they're indeed looking at a planet.
At 12 million years old, the team calls PSO J318.5-22 a "newborn" relative to most other planets, which could make it an interesting study tool for astronomers, and the fact that it's not getting any light from a nearby sun will apparently only enhance the learning potential.
"PSO J318.5-22 is not orbiting a star, so it will be much easier for us to study," study co-author Niall Deacon of the Max Planck Institute for Astronomy said. "It is going to provide a wonderful view into the inner workings of gas-giant planets like Jupiter shortly after their birth.”
So, for the first time, we've got confirmation of a planet that's simply drifting in space, but according to Liu, we shouldn't expect it to be the last.
"I'm very optimistic that we will find several more of these in the next couple years," he said.
You can read the full statement from the PSO J318.5-22 team here.
(Via Huffington Post)