Polarization measurements of Vega-like stars

Abstract

Optical linear polarization measurements are presented for about 30 Vega-like stars. These are then compared with the polarization observed for normal field stars. A significant fraction of the Vega-like stars are found to show polarization much in excess of that expected to be due to interstellar matter along the line of sight to the star. The excess polarization must be intrinsic to the star, caused by circumstellar scattering material that is distributed in a flattened disk. A correlation between infrared excess and optical polarization is found for the Vega-like stars.