Revised CE development criteria for stars with 10% of solar metallicity. On horizontal axis is the mass of the donor star. On the vertical axis is the radius of the donor. The circle and square points mark values of R_S and R_U, respectively (see Table 2). We fit lines to these data (see Eqs. (4)–(6)) to show regions of stable RLOF and unstable RLOF (CE). The color coded bar on the right denotes companion mass.