Most of the stars we see are in fact more than one star, and typically they are binary systems where one star orbits another. In some cases one star begins to gobble up its companion and it can turn into what is known as a cataclysmic variable where the star system brightens and dims as it gobbles, burps, and the rests a while. Or something like that - Dr Valerio Ribeiro from the University of Aveiro in Portugal tells us how.