Kinematics of Cataclysmic Variables in the Solar Neighborhood in the Gaia Era

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 sigma(nu) = 46.33 +/- 4.23 km s(-1), indicating that the thin disk CVs with a mean kinematical age of tau = 3.95 +/- 0.75 Gyr are much younger than the local thin disk of the Galaxy with tau similar to 6-9 Gyr. Total space velocity dispersions of nonmagnetic CVs belonging to the thin disk component of the Galaxy were found to be sigma(nu) = 47.67 +/- 3.94 and sigma(nu) = 44.43 +/- 4.33 km s(-1) for the systems below and above the orbital period gap, respectively, corresponding to kinematical ages of tau = 4.19 +/- 0.71 and tau = 3.61 +/- 0.74 Gyr. gamma velocity dispersions of the thin disk CVs below and above the gap were obtained sigma(gamma) = 27.52 +/- 2.28 and sigma(gamma) = 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) x 10(-5) s yr(-1). However, a significant difference could not be found between the gamma velocity dispersions of the systems below and above the gap, which were calculated to be sigma(gamma) = 27.52 +/- 2.28 and sigma(gamma) = 25.65 +/- 2.44 km s(-1), respectively.