Abstract As cataclysmic variables (CVs) that have evolved past their minimum orbital period, period bouncers have been proposed to be a substantial fraction of the CV population, yet the observed number is significantly lower, posing the “missing bouncer” problem. In this work, we present a multiband photometric selection method to search for new period bouncer candidates. We identify a specific locus for confirmed bouncers in the optical-UV-IR space. Using this locus, we selected 430 candidates within 500 pc. Crossmatching with eROSITA and XMM-Newton catalogs reveals 10 candidates (seven of which are new) with X-ray emission, indicative of accretion. X-ray spectral analysis of these candidates confirmed plasma temperatures consistent with confirmed bouncers. Based on these findings, we estimate a local space density of high-likelihood period bouncer candidates of approximately 4.1 × 10 −7 pc −3 . The nature of these candidates requires confirmation through follow-up observations.
Xu et al. (Fri,) studied this question.