Faraday Rotation Variability Study in the Gamma Ray Emitting High Mass X-ray Binary LSI +61° 303

LSI +61 303 is one of five known gamma-ray loud and radio-loud high-mass X-ray binaries (HMXB). We conducted polarimetric observations on LSI +61 303 over three orbital periods using the Karl G. Jansky Very Large Array (VLA). These sessions occurred on 2019 November 10, November 20, December 7, December 14, December 29, 2020 January 9, January 14, and January 18. Our observations covered between 4.82 and 9.5 GHz. In the context of our research, we report Faraday rotation measurements, which is the rotation of the plane of polarization of a radio wave as it passes through one or more magneto-ionic environments. We also discussed the fractional polarization and spectral index in the context of orbital period and the literature. Pulsations in the system were reported by Weng et al. (2022 Nature Astronomy, 6, 698) based on observations with the Five-hundred-meter Aperture Spherical Telescope (FAST), which provide compelling evidence that the compact object is a rotating neutron star, i.e., a pulsar. In our discussion, we adopt their conclusion regarding the nature of the compact object.