A Multicolor Study of Polarization Variability in Isolated B[e] Stars HD 45677 and HD 50138

Abstract HD 45677 and HD 50138 are two B[e] stars isolated from any known star-forming regions. We investigated the polarization characterization of their surrounding gas and in situ dust in the inner edge of the circumstellar disk. Our measurements of the intrinsic polarization of each star between 2010 and 2011, after correcting for foreground polarization through field star observation, reveal a decreasing level of polarization with wavelength, with the polarization angle independent of wavelength. However, reanalysis of literature data by applying our foreground correction method clarified the relative roles of electron scattering versus dust scattering in the circumstellar disk. Combining the multicolor data from the available epochs led us to conclude that a general electron scattering-dominated disk exists in both B[e] stars, with evidence of micron-sized grains seen at some epochs, likely condensed in the inner disk.