Study of variability of the polarization in Herbig Ae/Be stars

Abstract

We report our measurements of linear polarization of a number of Herbig Ae/Be stars made at several epochs during the period 1989-1993. These results together with the observations compiled from the published sources have been analysed to study the variability of polarization in Herbig Ae/Be stars. It is found that polarimetric variability is a common feature of this class of objects. Most of the objects are variable on time scales >=1yr. Some objects have shown large variations on time scales as short as ~1 month indicating structural changes in the distribution of circumstellar matter close to the star within a few tens of stellar radii. Variations in the polarization position angle are not always correlated with variations in the degree of polarization.