“It goes to show that there’s something we don’t know about our Solar System, and it’s something important,” says co-discoverer Chad Trujillo, an astronomer at Gemini Observatory in Hilo, Hawaii. “We’re starting to get a taste of what’s out beyond what we consider the edge.”
"A rogue planet could have been ejected from our solar system and perturbed their orbits," says astronomer Scott Sheppard of the Carnegie Institution for Science in Washington, D.C., who coauthored the discovery report in the journal Nature. "Definitely, it could still be out there."
The journal article reports on what they know for a fact. Another planet on an unusual orbit is speculation for now, so I'm not surprised they didn't mention it - although I hope that as they gather more data they'll be able to infer its location and see it block stars or somesuch, if it exists.
An inner Oort Cloud object? Interesting. And apparently Sedna is also an Oort Cloud object? I did not know that. I thought it was a Kuiper Belt object.
I've always dismissed that as pseudoscientific nonsense, but it would be amusing if fringe astronomers like Zechariah Sitchin turned out to be even partially correct.
Also it could be a brown dwarf which are hard to detect but will be inline with typical binary star systems observed elsewhere. It is hardly unlikely that our own sun is an exception to the rule.
Not to mention, the 'nemesis' theory is speculated by some main-stream astronomers.
http://www.nature.com/news/dwarf-planet-stretches-solar-syst...
“It goes to show that there’s something we don’t know about our Solar System, and it’s something important,” says co-discoverer Chad Trujillo, an astronomer at Gemini Observatory in Hilo, Hawaii. “We’re starting to get a taste of what’s out beyond what we consider the edge.”