Visual Orbits and Alignments of Planet-hosting Binary Systems

Abstract

Roughly half of Solar-type planet hosts have stellar companions, so understanding how these binary companions affect the formation and evolution of planets is an important component to understanding planetary systems overall. Measuring the dynamical properties of planet host binaries enables a valuable test of planet formation in multistar systems and requires knowledge of the binary orbital parameters. Using high-resolution imaging, we have measured the relative astrometry and visual orbits of 13 binary systems where one of the stars is known to host a transiting exoplanet. Our results indicate that the mutual inclination between the orbits of the binary hosts and the transiting planets are well aligned. Our results for close binary systems ( a < 100 au) complement past work for wide planet host binaries from Gaia.

Keywords

• Binary stars
• Exoplanet systems
• Planet hosting stars
• Astrometric binary stars