Interactions between the magnetorotational and magnetic buoyancy instabilities in a compressible conducting fluid

Magnetohydrodynamic instabilities are believed to play an important role in the evolution of astrophysical objects such as stars and accretion disks. Magnetic buoyancy instability (MBI) appears when the toroidal magnetic field in a conducting medium decreases in the direction opposite to the gravity. It is a probable mechanism for emerging plasma and strong magnetic field from deep regions to the surface of a star, which causes starspots or stellar prominences. Magnetorotational instability (MRI) arises when the angular velocity of a rotating conducting fluid in a magnetic field decreases as the distance from the rotation center increases. This phenomenon probably explains the fast accretion of matter into massive objects such as stars and black holes. During the presentation, I will show the results of the analytical and numerical approach to the problem of the interaction between those two instabilities in the plane layer of a compressible conducting fluid.