Well, it could be an artifact in the ALMA imagery, but this could be a Solar System object. It could be a trans-Neptunian object beyond 100 AU, perhaps maybe even a brown dwarf or super-Earth. There's no way to know at this time however, so discuss here.
http://www.forbes.com/sites/briankob...-solar-system/
https://en.wikipedia.org/wiki/U_%28TNO%29