Most of the planets were formed around young stars. But can they also form around dying stars? The origin of the diversity and complexity of the detected exoplanetary systems stems from how they form in protoplanetary disks. These disks are intensively studied around young stars thanks to the high-angular resolution provided by recent instruments (VLT, ALMA). However, similar disks are also found around evolved stars, namely post-AGB binaries, raising the exciting but yet unanswered possibility of second-generation planet formation. Do planets form around evolved stars? While this question has only been tackled theoretically in the past, we have now the possibility to probe such second-generation planet formation by observations using high angular resolution instruments.

In this talk I will show the latest results of an extensive high angular resolution observing campaign of these disks using infrared interferometry at the VLTI (PIONIER, GRAVITY, MATISSE). I will show that these disks share many similarities with protoplanetary disks around young stars. These disks are, therefore, a unique laboratory to test planet formation processes in a parameter space that is unmet around young stars (e.g., short disk lifetime, high stellar luminosity, lack of influence from the environment). Whether or not planet formation is possible at the end of stellar evolution, studying it in a very different parameter space will provide an unprecedented test to current planet formation theories.