Until recently, astronomers only knew about exoplanets which, like those in our own solar system, orbited a single star. Then, the first one was discovered which orbits two stars, much like Tatooine in the Star Wars films. Since then, other similar planets have been found, indicating that such circumbinary planets (those which orbit double stars) may be fairly common.
Now, the Kepler space telescope has one-upped even those discoveries, finding the first known planet in a four-star system.
(This article was first published on Examiner.com)