SIMBAD references

A kinematical study of rapidly oscillating Ap (roAp) stars and of a sample of apparently similar Ap stars that show no pulsation is performed, with a view to investigating possible differences between the two groups. The mean absolute magnitudes of the stars of both samples, derived through the mean parallax method, are at most marginally different. From the consideration of the velocity ellipsoid parameters and of the mean orbital elements characterizing their motion in the Galaxy, the roAp stars appear significantly older than their non-pulsating counterparts.