Sun is binary star system

From Slackerpedia Galactica

An interesting little equivalent of a nutty conspiracy theory in astronomy, this is the idea that we may in fact be part of a binary star system and not even know it because the Sun's twin is hidden, such as a red dwarf, white dwarf, or black hole. Jupiter has been theorized to have been close to a second star in our Solar System, for example. Most data doesn't seem to corroborate this except that something huge and dark may be messing up the orbits of Pluto, comets, and other Kuiper Belt Objects.

An interesting idea, but not taken too seriously. Of course, they thought Eris was just as much of a stupid theory too.