Photometric activity and rotational velocities of ux ori stars and related objects

The rotational velocities of young stars of the UX Ori type and related objects are analyzed. It is shown that there is a weak but statistically significant correlation between υsin i and the amplitudes of photometric variability of these stars. It reflects the fact that the brightness variability of this type of star is determined mainly by variations in the column density of circumstellar dust along the line of sight. The latter depends, in turn, on the orientation of the circumstellar disk and is greatest when the disk is oriented edgeon to the observer or at a small angle to the line of sight. Translated from Astrofizika, Vol. 43, No. 3, pp. 329-337, July– September, 2000.