"The planet's called Tatooine." - Luke Skywalker, in the Star Wars novelization. OK, it isn't but it might as well be. For a long time, scientists were not sure whether you could have a stable planetary system around a double star. Thanks to the Kepler telescope, we know you can. Kepler-16b, about the diameter of Saturn, exists 200 light years away. SInce most of the stars we've observed are in binary systems, this greatly increases the possible number of planetary systems.
COMMENT: The universe is more diverse, weirder, and more exotic than we used to know or even theorize - and that is proved all over again seemingly every year.