Near-simultaneous Spectroscopic and Broadband Polarimetric Observations of BE Stars

Abstract

Near simultaneous optical spectroscopic (on four nights) and broadband linear continuum (B, V, R,and I bands) polarimetric (on seven nights) observations of 29 Be stars were carried out during 1993November-December. The program Be stars displayed wavelength dependence of intrinsic polarizations with no frequency dependence of polarimetric position angles. Some of the Be stars displayed long-term polarization variability. The Be and Be-shell stars could not be distinguished from one another solely on the basis of their polarization values. Full widths at half-maximum of the Hα profiles and the intrinsic linear continuum polarizations are closely correlated with the projected rotational velocities of the program stars. Photospheric-absorption-corrected equivalent widths of Hα profiles [W(alpha)] and the radii of Hα-emitting or -absorbing envelopes (R_e or R_a) are nonlinearly correlated with the intrinsic continuum polarizations of these stars. However, W(alpha) and R_e are linearly correlated. With large uncertainties, there is a trend of spectral dependence of polarization. Detailed discussion of these results is presented in this paper.