... ESO . ... Star Clusters . ... Stars@ESO . ... A series of very detailed images of a binary system of two young stars have been combined into a movie. ... This is the first time such an accurate determination of the stellar masses could be achieved for a young binary system of low-mass stars. ... Few systems are known for which such precise determinations of the stellar parameters have ever been possible - and this binary system represents the first case where both the components are such young stars...