Bonnor–Ebert mass

Summary

The Bonnor–Ebert mass is the largest mass of an isothermal gas sphere in stable hydrostatic equilibrium under a given external pressure. A more massive sphere at the same temperature and external pressure must collapse. It is the analogue of the Jeans mass for a cloud of finite size. It is used to judge whether dense cores in molecular clouds will form stars. The equilibrium spheres themselves are called Bonnor–Ebert spheres.