Modeling of the L\({}_{1}\) Point Jet Formation in Binary Star Her X1

Observational data from the binary X-ray star system Her X1 indicate that the accretion disk in it is tilted and precesses with a period of about 35 days. Precession leads to unbalanced heating of the donor star and, as a consequence, to nonuniform outflow from its surface. A mathematical model has been developed for the outflow of matter from the surface of a star under the action of heating by an accretor, taking into account the shadow from the accretion disk. The model includes a 3D system of equations for the dynamics of an inviscid partially ionized gas, taking into account gravity and radiation effects. The algorithm is adapted to the use of tetrahedral meshes and takes into account the shadow displacement on the donor surface. Calculations have shown that the presence of a shadow leads to a displacement of the gas flow in the vicinity of the Lagrangian point L \({}_{1}\) . The center of the stream moves up and down, and its shape changes according to the movements of the shadow. Such an effect can lead to a tilt of the accretion disk, which makes the model self-consistent.