A comment on the properties of the matter flow through the first Langrangian point

We analyse properties of the mass outflow from Roche-lobe filling component a semi-detached binary system. follow approaches published by Paczy\'nski \& Sienkiewicz and Lubow Shu, which we compare with other simplified approaches. find that density flow at $L_1$ is orders magnitude lower than on same equipotential but away $L_1$. Furthermore, effective cross section flow, after averaging over its profile momentum density, much some estimates done without accounting for averaging. Thus, use formulae can lead to overestimates accretion rate contained in regions very large factors unless they are supported simultaneous integrations equations stellar structure outer layers donor.