The project has three objectives,
a unique, dedicated campaign using the 1.2-m telescope of Athens Observatory on an X-ray nova (1-2 per year) harbouring a black-hole candidate over many months,
the application of the maximum entropy method (used in medical X-ray imaging) on X-ray binaries harbouring neutron stars or black-hole candidates to probe structure on scales of 0.1-10 light seconds utilizing simultaneous observations of the X-ray Timing Explorer and large telescopes (echo tomography),
and the application of star atmospheres in modelling observed accretion disc spectra, utilizing the state-of-the-art code by Hybeny (NASA), to probe the radial and vertical structure of quiescent accretion discs. The introduction of the above pioneering projects (observational campaign, mathematical technique and novel astrophysical analysis) will be accomplished during the return fellowship with the aim to transfer them to the Greek scientific community in the medium term.