2025AJ....169...87C

Using high-precision astrometric data from Gaia DR3 and updated systemic velocities from the literature, the kinematical properties of cataclysmic variables (CVs) were investigated. By constraining the data according to the total space velocity error and Galactic population class, a reliable sample of data was obtained. Nonmagnetic CVs located in the thin disk have been found to have a total space velocity dispersion of σ_ν = 46.33 ± 4.23 km s^–1, indicating that the thin disk CVs with a mean kinematical age of τ = 3.95 ± 0.75 Gyr are much younger than the local thin disk of the Galaxy with τ ∼ 6-9 Gyr. Total space velocity dispersions of nonmagnetic CVs belonging to the thin disk component of the Galaxy were found to be σ_ν = 47.67 ± 3.94 and σ_ν = 44.43 ± 4.33 km s^–1 for the systems below and above the orbital period gap, respectively, corresponding to kinematical ages of τ = 4.19 ± 0.71 and τ = 3.61 ± 0.74 Gyr. γ velocity dispersions of the thin disk CVs below and above the gap were obtained σ_γ = 27.52 ± 2.28 and σ_γ = 25.65 ± 2.44 km s^–1, respectively. This study also shows that the orbital period is decreasing with increasing age, as expected from the standard theory. The age-orbital period relation for nonmagnetic thin disk CVs was obtained as dP/dt = -2.09( ± 0.22) × 10^–5 s yr^–1. However, a significant difference could not be found between the γ velocity dispersions of the systems below and above the gap, which were calculated to be σ_γ = 27.52 ± 2.28 and σ_γ = 25.65 ± 2.44 km s^–1, respectively.