White dwarfs are the final fate of 95 per cent of all stars, including our Sun. Planets and planetary bodies that survived this metamorphosis of their host star can venture close to the left-ove stellar cores (i.e. white dwarf) where tidal force results in their disruption. A debris disc is formed and its material accretes onto the white dwarf. Observational evidence is widely supporting this framework.
However, the number of systems is very small for statistics and population studies, and hence our efforts with MOS surveys to enlarge the samples. On the modelling point of view, the chemical composition of the parent bodies is extracted from UV/OPTICAL spectroscopy of white dwarfs. A key assumption, and so far untested, is that the pollution caused by the accreted fragments on the white dwarfs are homogeneous. Here, I will present the current status of what we know of these evolved planetary systems, our progress with MOS SDSS-V survey and a test on the the homogeneity of the the metal distribution using a pulsating white dwarf G29-38.