Effect of the Orbit Eccentricity on the Flow in the Envelope of a Hot Jupiter

three-dimensional numerical gas–dynamic model is presented. The aim of the model is to study the structure of the flow in the envelopes of hot Jupiters with elliptical orbits. To increase the speed and improve the accuracy of the simulation, the calculation is carried out in a noninertial frame of reference that is moving along with the planet in an elliptical orbit. The proper rotation of the coordinate frame is set in such a way as to maintain a constant direction to the star. This way it is possible to simplify the equations used in the simulation and to perform calculations on nonuniform grids, avoiding accuracy losses caused by the motion of the planet along the grid. A calculation is conducted for the flow structure in the extended envelope of a hot Jupiter moving in an orbit with an eccentricity of e = 0.2 . It is shown that the orbit eccentricity leads to periodic variations in the flow of gas lost by the planet’s atmosphere after the planet passes the periastron. The average mass loss rate is roughly the same as the quantity obtained in the model with a circular orbit for the same size of the semimajor axis.