The formation of a helium white dwarf in a close binary system with diffusion

Abstract

We study the evolution of a system composed of a 1.4-M neutron star and a normal, solar composition star of 2 M in orbit with a period of 1 d. Calculations were performed employing the binary HYDRO code presented by Benvenuto & De Vito that handle the mass transfer rate in a fully implicit way. We then included the main standard physical ingredients together with the diffusion processes and a proper outer boundary condition. We have assumed fully non-conservative mass transfer episodes.