B, V and R band polarimetry of lambda Tau

The data have been obtained on the 60cm KVA (Observatory Roque de los Muchachos, La Palma, Spain) and Tohoku 60cm (Haleakala, Hawaii, USA) remotely controlled telescopes during 69 observing nights. Optical polarimetry revealed small intrinsic polarization with ~0.05% peak to peak variation over the orbital period of ~3.95d.

Variability pattern is typical for binary systems showing strong second harmonic of the orbital period. We apply a standard analytical method and our own light scattering models to derive parameters of the inner binary orbit from the fit to the observed variability of the normalized Stokes parameters. Analytic and numerical modelling codes are used to interpret the data.