I agree with Brian that a 100 AU sub-Pluto is the simplest explanation.

I agree with Brian that a 100 AU sub-Pluto is the simplest explanation. I look forward to hearing more about this object.

Originally shared by Brian Koberlein

Astronomers Find New Object, Possible Super-Earth In Our Solar System

There’s reason to be cautious about this discovery. The fact that it’s so close to the apparent direction of Alpha Centauri is unusual at best, but this could potentially be a very big discovery.

http://www.forbes.com/sites/briankoberlein/2015/12/10/astronomers-find-new-object-possible-super-earth-in-our-solar-system/