Local Variations of the Velocity Ellipsoid

We have analyzed the distribution of residual velocities of nearby stars (within 200 pc of the Sun) looking for space variations on the velocity ellipsoid. We used a sample of 1071 main sequence stars of spectral types B, A and F selected from the Hipparcos Input Catalogue [7] with uvbyH, s photometric data. Ages have been calculated following [1]. Six subsamples with 8.07 ≤ log(age) ≤ 9.45 have been considered.