Princeton University Extrasolar Planet Discussion Group

We present a catalog of stellar companions to host stars of TESS Objects of Interest identified from a marginalized likelihood ratio test that incorporates astrometric data from the Gaia Early Data Release 3 catalog (EDR3). The likelihood ratio is computed using a probabilistic model that incorporates parallax and proper motion covariances and marginalizes the distances and 3D velocities of stars in order to identify comoving stellar pairs. We find 189 comoving companions to 186 non-false positive TOI hosts, consisting of 183 systems with two stars and 3 systems with three stars. Amongst the 186 TOI hosts, 48 harbor confirmed planets that span a wide range of system architectures. We conduct an investigation of the mutual inclinations between the stellar companion and planetary orbits. While the statistical significance of the current sample is weak, we find that 73+14-20% of systems with Kepler-like architectures (Rp ≤ 4 REarth and a < 1 AU) prefer a non-isotropic orientation between the planetary and companion orbits with a typical mutual inclination α of 35 +/- 24 degrees. In contrast, 65+20-35% of systems with close-in giants (P < 10 days and Rp > 4 REarth) favor a perpendicular geometry (α = 89 +/- 21 degrees) between the planet and companion. Moreover, the close-in giants with large stellar obliquities (planet-host misalignment) are also those that favor significant planet-companion misalignment.