Multiplicity of stars with planets

We aimed to assess how stellar multiplicity affects exoplanets’ presence and properties. We analysed all exoplanet host stars within 100 pc using Gaia DR3 data, advanced statistical methods, and additional information from the Washington Double Star catalogue and literature. Identified 215 exoplanet host stars in 212 multi-star systems, discovering 17 new companions in 15 known systems. Our findings showed differences in the average number of planets in multiple versus single systems and a tendency for high-mass planets to orbit closer in multiple systems. We confirmed that planets in multiple systems generally have higher orbital eccentricities, with a significant trend towards high eccentricities when star-star separations are small compared to star-planet distances.