WDs in open clusters and tidal tails

We identify 235 OC-WD pairs in 80 clusters, including 99 WDs in tidal tails. More than 28% of the pairs are likely spurious, with contamination substantially higher in the tails (>48%) than in the cluster cores (>13%), indicating significant field-star contamination in current Gaia-based catalogues. The Pleiades tidal tails also show severe contamination by old WDs.

Simulations predict that the fraction of core WDs increases with cluster age, reaching >10%, whereas the observed fractions remain systematically lower, consistent with the WD deficit problem. Despite the high contamination rate, most tail WDs (~83%) are consistent with having been born inside the tidal radius. We additionally identify 63 candidate binary-origin WDs and 47 new IFMR candidates.

WDs provide a powerful probe of contamination in cluster and tidal tail catalogues and place important constraints on cluster detection methods and N-body simulations. Resolving the WD deficit and improving membership validation will require improved observations, membership methods, WD physics, and spectroscopic follow-up, ultimately enabling stronger constraints on dynamical cluster evolution and the WD IFMR.