Compact objects (black holes, neutron stars and white dwarfs) play a major role in modern astrophysics. They are associated with the most exotic environments and violent phenomena of the Universe. Surrounded by extremely powerful gravitational and magnetic fields, they appear as luminous X-ray or gamma-ray sources, thus allowing scientists to explore certain physical processes under conditions that cannot be obtained in laboratories.

Astrophysicists involved in the study of compact objects focus on a number of key issues: the validity of the theory of gravitation in strong fields, the physical phenomena associated to the accretion of matter and to the emission of relativistic jets, the nature of particle acceleration in extreme magnetic fields, nucleosynthesis processes of supernovae, the formation and evolution of black holes.