The Search for Stellar Companions to Exoplanet Host Stars Using the CHARA Array

TL;DR

This study used the CHARA Array interferometer to search for stellar companions around 22 exoplanet host stars, aiming to detect low-inclination stellar companions that could be mistaken for planets.

Contribution

It demonstrates the application of interferometry to rule out certain stellar companions in exoplanet systems, improving understanding of their true nature.

Findings

No definitive stellar companions were detected.

Certain secondary spectral types were ruled out for each system.

Interferometric methods can effectively constrain stellar companions.

Abstract

Most exoplanets have been discovered via radial velocity studies, which are inherently insensitive to orbital inclination. Interferometric observations will show evidence of a stellar companion if it sufficiently bright, regardless of the inclination. Using the CHARA Array, we observed 22 exoplanet host stars to search for stellar companions in low-inclination orbits that may be masquerading as planetary systems. While no definitive stellar companions were discovered, it was possible to rule out certain secondary spectral types for each exoplanet system observed by studying the errors in the diameter fit to calibrated visibilities and by searching for separated fringe packets.