Don’t you mean ‘We have a new theory’? From your article: “For a long time, we thought the occasional merger of two low-mass stars gave rise to a heavier, blue star. But there’s *an alternative*.” “Combined with an earlier study, this *causes a complete rethink* of blue stragglers.” By See Noevo (not verified) on 14 Dec 2015 #permalink Within a star cluster, what is the agent which keeps the separation of the individual members from collapsing into a central mass? By PJ (not verified) on 14 Dec 2015 #permalink @PJ: Angular momentum, basically. The stars in the cluster are all moving around the center of mass of the whole system. Without some mechanism to significantly slow them down, they'll maintain those orbits indefinitely.