Two suns Planet

Thirty-four years ago George Lucas imagined a story taking place "in a galaxy far, far away"; down there, among the thousands of extrasolar systems, was Tatooine, the home planet of the protagonist of the Saga, Luke Skywalker. Planet that was located in a very particular solar system, which offered this type of show at sunset: Tatooine was in fact in orbit not with one, but with two stars, so two suns were visible in its sky. Until now, the search for extrasolar planets had focused on single stars, as it was not possible to know whether "double" or "binary" stars were also capable of existing in a stable system with planets; now that it is certain, the search will also be able to extend to binary stars; stars which until now were instead viewed not very favorably, in a certain sense, by "planet hunters", since binary stars are one of the most frequent "false positives" in this type of research; to identify extrasolar planets, in fact, among others, the "eclipse" method is used, i.e. the brightness of a star is constantly monitored: if it decreases, it means that "something" has passed between the star and the observer; in this case we speak of "possible planet" or "candidate planet"; However, if it turns out that it is not a planet that eclipses the star, but another star, you have a false positive. The phenomenon of extrasolar eclipses as seen from Earth is well illustrated in this animation, which shows how the brightness curve varies as the planet passes: http://kepler.nasa.gov/multimedia/AnimationsandMore/animations/?ImageID=38 The discovery of this particular system was possible thanks to the very high sensitivity of the sensors on board Kepler, which allowed us to discern the presence of the planet within the brightness curve, as illustrated in these figures:
Fonti: http://technews.it/MWGPD