Polarization during microlensing of binary stars

The microlensing effect can be used to solve a variety of astronomical problems. It would undoubtedly be of interest to use this phenomenon as an efficient extraterrestrial telescope with extremely high angular resolution. The recorded total flux should become partially polarized in the microlensing process. The application of the microlensing effect to observe close binaries is discussed, and the polarization of light during a binary microlensing event is considered. The extraction of information from microlensing light curves is described. The time dependence of the degree of polarization is found, and the change in the polarization curve when the binary star passes through the Einstein cone is determined. Polarization curves constructed for various parameters of the source-lens-observer system are presented. Calculations show that, in some cases, changes in the level of polarization as large as 0.03% can be expected.