Cataclysmic variables with degenerate donors which have evolved past the period minimum, also known as period-bouncers, are predicted to make up a great portion of the cataclysmic variable population, between 40% and 70%. However, either due to shortcomings in the models or due to the intrinsic faintness of these strongly evolved systems, only a few have been confidently identified so far. We have compiled a multi-wavelength catalog of period-bouncers and cataclysmic variables around the period minimum (Porb~80min) from the literature in order to provide an in-depth characterization of the elusive subclass of period- bounce CVs that will help in the identification of new candidates. In this study we combine published or archival multi-wavelength data with new X-ray observations from the all-sky surveys carried out with the extended ROentgen Survey with an Imaging Telescope Array (eROSITA) onboard the Spektrum- Roentgen-Gamma spacecraft (SRG). We compiled a scorecard that is able to rate how likely a system is of being a period-bouncer that, together with X-ray selection cuts established from the eROSITA detected known period-bouncers, resulted in the confirmation of 7 systems as new period-bouncers. This brings the population of confirmed period-bouncers to 24 systems, corresponding to a ~40% increase. Our "scorecard" correctly assigns high scores to the already confirmed period-bouncers in our literature catalog and it identifies 80 additional strong period-bounce candidates present in the literature that have not been classified as such. We established two selection cuts based on the X-ray-to-optical flux ratio (-1.21<=log(Fx/Fopt)<=0) and the typical X-ray luminosity (log(Lx,bol)<=30.4[erg/s]) observed from the 8 already confirmed period-bouncers with eROSITA data. These X-ray selection cuts led to the categorization of 5 systems as new period-bouncers, increasing their population number to 22 systems. Our multi-wavelength catalog of cataclysmic variables around the period minimum compiled from the literature together with X-ray data from eROSITA resulted in a ~30% increase in the population of period-bouncers. Both the catalog and "scorecard" that we constructed will aid in future searches for new period-bounce candidates with the goal of resolving the discrepancy between the predicted high number of period-bouncers and the low number of these systems that have been observed to date.

Cone search capability for table J/A+A/687/A305/tableb2 (Complete catalog of period-bouncers and CVs around the period minimum)