  The discovery that the Galactic centre emits flares at various wavelengths
represents a puzzle concerning their origin, but at the same time it is a
relevant opportunity to investigate the environment of the nearest
super-massive black hole. In this paper we shall review some of our recent
results concerning the tidal evolution of the orbits of low mass satellites
around black holes, and the tidal effect during their in-fall. We show that
tidal interaction can offer an explanation for transient phenomena like near
infra-red and X-ray flares from Sgr A*.

High Energy Astrophysical Phenomena;Astrophysics of Galaxies