Genesis of Binary Stars Numerical simulations of collapsing clouds of primordial gas indicate that the first luminous objects to form in the universe were isolated massive stars. Turk et al. (p. 601 , published online 9 July) now show that it is possible for single primordial clouds to break up into two dense cores. Three-dimensional calculations, which follow the evolution of primordial gas (composed of hydrogen and helium, with traces of deuterium and lithium) and dark matter starting from realistic, cosmological initial conditions, suggest that these cores may evolve to form binary star systems.

The Formation of Population III Binaries from Cosmological Initial Conditions