Age Estimate of Novel White Dwarf Open Cluster with Abnormal Proper Motions

Abstract

White dwarf open clusters can provide significant insight into the Milky Way local spiral structure as ancient tracers. We analyze a sample of 20 high-confidence white dwarfs from Gaia EDR3 and DES Y6 Gold Release with abnormal proper motions and positioning in color space. We make use of previously derived stellar parameters and theoretical white dwarf cooling sequences to estimate cooling ages for this sample, and by extension a potential new open cluster. We present 11 of the objects as candidate open cluster members, and estimate a cluster cooling age of 2.2(1.0) Gyr. We finally discuss ways to reduce age estimate uncertainties and how these findings can be used to further probe the local spiral structure.