Gaia Astrometry Challenges the High Central Oxygen Abundance Claimed for the Pulsating Helium-Atmosphere White Dwarf KIC 08626021

Abstract The asteroseismic radius determination previously reported for the pulsating helium-atmosphere white dwarf star KIC 08626021 is 6σ discrepant with constraints from Gaia astrometry. This calls into question the other results of the asteroseismic analysis, especially the high (central) oxygen abundance that stellar evolutionary models have been unable to reproduce.