Flow Structure near an Island in a Shallow Strait

The problems of flow dynamics in a near-island zone of a shallow channel is considered using as an example the Bjerkezund Strait (eastern Gulf of Finland). Preliminary results of field studies and the results of numerical modeling of water circulation in the strait are given.     

The libration points for the motion of a star inside an elliptical galaxy

We consider the three-dimensional motion of a star inside an inhomogeneous, rotating, elliptical galaxy with a homothetic density distribution. The libration points inside a triaxial, rotating, inhomogeneous, gravitating ellipsoid are determined and their stability studied. We determine zero-velocity surfaces and regions of possible motion both inside and outside the galaxy. The motions are shown to be stable in the sense given by Hill. The obtained zero-velocity surfaces enable the construction of a Roche model for a galaxy in the form of either a triaxial ellipsoid or an oblate ellipsoid of rotation.