An international group of astronomers, including Jonathan Tan from the University of Virginia, have made observations of a molecular cloud that is collapsing to form two massive protostars that will eventually become a binary star system. The observations showed that, even at this early stage, the cloud contains two objects: a massive “primary” central star and another “secondary” forming star, with a combined mass of at least 18 times that of our Sun. For the first time, the researchers were able to use these observations to deduce the dynamics of the system.